





'.^ 



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Glass. 
Book- 



COPYRIGHT DEPOSIT 




Courtesy of The B. F. Goodrich Co. 

THE SOURCE OF RjfW RUBBER TAPPING A RUBBER TREE IN MAYLAYA 



THE 
REIGN OF RUBBER 



BY 
WILLIAM C. GEER, A.B., Ph.D. 

Vice-President, The B. F. Goodrich Company, Akron, Ohio 



ILLUSTRATED WITH 
MANY PHOTOGRAPHS 







NEW YORK 

THE CENTURY CO. 

1922 






Copyright, 1922, by 
The Century Co. 



I 



^ 



PRINTED IN 0. S. A- 



OCT -2 72 

©C1A683486 

1.5 f I 



This book is dedicated to 

Mr. BERTRAM G. WORK 

under whom the author first became 

acquainted with rubber 



ACKNOWLEDGMENT 

Happy is he who has found a wealth of cordial co-opera- 
tion. Such assistance to me in the preparation of this book 
has been noteworthy. 

The' aid of Miss Frances McGovern and Mr. W. Don Har- 
rison of Akron has been especially valuable. 

In the gathering of material and data many have heartily 
assisted. It would be impracticable to mention all, but 
among them are: Professor William H. Goodyear, Curator 
of Fine Arts at the Brooklyn Museum; the officials of The 
United States Eubber Company, The Fisk Rubber Company, 
The Firestone Tire and Eubber Company, The Goodyear 
Tire and Rubber Company, The Boston Woven Hose and 
Rubber Company; my associates, the executives of the B. 
F. Goodrich Company, and many of the staff; A. G. Spalding 
& Bros.; Brigadier General Amos A. Fries of the Chemical 
Warfare Service, United States Army; the officials of the 
Bureau of Aeronautics, United States Navy; the officials of 
the Air Service, United States Army; The Rome Wire Com- 
pany; Mr. C. R. Boggs of the Simplex Wire and Cable Co.; 
M. A. Cillard, Editor of Le Caoutchouc et La Gutta-Percha, 
Paris; Mr. W. M. Morse, Editor of the India Rubber World; 
Mr. J. K. Mitchell, President of the Philadelphia Rubber 
Works Company; Mr. Oswald Latham and Mr. Herbert 
Standring of London; and Mr. W. E. Hemenover. 



CONTENTS 

CHAPTER PAGE 

' I The Evolution of an Industry 3 

II Problems of a Pioneer 18 

III Fundamental Methods and Machinery .... 29 

IV* The Rubber Man's Cook-Book . 44 

V Raw Rubber 63 

VI Reclaiming Waste 88 

. VII The Chemistry of Rubber Mixtures 99 

VIII The Bicycle Tire 120 

IX The Pneum\atic Automobile Tire 128 

X Transportation by Truck 149 

XI Water-Proof Footwear and Clothing .... 168 

XII Broadening the Field of Sport 187 

XIII Power and Light 205 

XIV Communication 217 

XV Fighting Fire 235 

XVI In the Service of Health 249 

XVII Belting, Packing, and Hose 264 

XVIII Rubber in the Home 283 

XIX Qas-Masks 298 

XX Balloons ., ■....). 312 

XXI The Future of Rubber 325 

Index 341 



LIST OF ILLUSTRATIONS 

TACING PAGE 

Tapping a Rubber Tree Frontispiece 

Sulphur Crystals Inside a Rubber Sheet 24 

Difference Between Vulcanized and Unvulcanized Rubber . . 24 

Washiil^ Crude Rubber 32 

Spreading Rubber Cement on Cloth 32 

Weighing Out Compounds 32 

Drying Rubber in Vacuum Dryer 49 

Drying Rubber in Air Dryer 49 

Various Weighed-Out Rubber Mixtures 51 

Autobiography of Four Rubber Compounds 51 

Mixing Rubber Compounds 52 

Frictioning Cloth with Unvulcanized Rubber 52 

Hancock's Pickle 52 

Small Set of Laboratory Mills and Calenders ..... 61 

A Vulcanizing Press 61 

A Rubber Testing Machine . 61 

A Rubber Plantation in Sumatra 64 

Coagulation Tubs of the Plantation 64 

Washing Coagulated Raw Rubber 64 

Field Hands Gathering Cotton 68 

Several Grades of Plantation and Wild Rubber 77 

Map Showing Sources of Rubber and Cotton 81 

Vulcanized Rubber Scrap 88 

Reclaimed Automobile Tires 88 



LIST OF ILLUSTRATIONS 

FACING PAGE 



Reclaimed Rubber Boots and Shoes 



Photomicrograph of Barytes, Zinc Oxides, Whiting and Carbon 
Black 112 

Fabric Tire Dissected 129 

Cord Tire Dissected 129 

Building a Cord Tire 132 

Tires Ready for the Vulcanizers 132 

The Unvulcanized Tire in the Mold 141 

Filling the Vulcanizers with the Molds 141 

Effect of Pressure and Overloading on Tires 144 

A Freight Truck 161 

One of the Trackless Trolleys 161 

Parts of a Solid Tire 176 

A Ladies' Slipper 176 

A Rubber Shoe Made on the Amazon . 176 

The Soling Calender 193 

At the Make-up Table 193 

Shoe Vulcanizing 193 

Vulcanizing Hot Water Bottles 208 

Making Golf Balls 212 

Wire Ready for the Vulcanizer 221 

Covering Wire with Rubber Insulation 221 

Braiding Wire with Cotton Thread 221 

An Army Field Switchboard . 225 

A Modem Telephone Switchboard 225 

Weaving Cotton Jacket of Fire Hose 240 

Vulcanizing Cotton Rubber-lined Fire Hose 240 

The Use of Rubber Hose at a Fire 248 

Gloves Ready to Be Dipped 257 



LIST OF ILLUSTEATIONS 

FACING PAGE 

The Enclosed Dipping Machine 257 

Operators Rolling and Binding Gloves 257 

Convey or Belt in Action 272 

Vulcanizing a Convey or Belt 272 

Applying Rubber Insulation on Garden Hose 280 

Braiding Machines Making Garden Hose 280 

Vulcanizing Garden Hose 280 

Forcing the Jar Ring Compound Through a Tubing Machine . 289 

Cutting Jar Rings from Vulcanized Tube 289 

Various Gas Masks and Helmets 304 

United States Navy Type Blimp Dirigible 321 

Spherical Balloon 321 

Caquot Kite Balloon 321 

Map of World Showing Registration of Motor Cars . . . 338 



THE REIGN OF RUBBER 



THE REIGN OF RUBBER 

CHAPTER I 
THE EVOLUTION OF AN INDUSTRY 

My purpose in writing this book is to confess to you 
who employ rubber goods in any way, who take home 
from shop or store the water-bottle, the garden-hose, 
or the tire, something of the successes, failures, limi- 
tations, and hopes of those whose lives are spent in 
the creation of rubber products. Mystery has sur- 
rounded rubber factories; secretiveness has been the 
watchword; the methods of manufacture have been 
little revealed. 

But the old days of competitive reticence are past. 
Because, perhaps, of the harmony engendered of the 
World War, rubber men are more friendly with 
each other. Exchange of ideas has been found 
of mutual value. Research in each of the many 
units of the rubber industry has developed to 
the point where it may be said that there are few 
secrets left. Thus the time has now come when the 
makers should take their friends, the users of rubber 
products, into their confidence. 

I shall be most happy if from this effort may come 
to you a clearer understanding of rubber commodities, 



4 THE REIGN OF RUBBER 

and a warmer sympathy toward the active partici- 
pants in this fundamental industry. 

We live in a world of things and forces, in which 
things are the visible evidences of ideas, and forces 
are the means through which the creation of things 
is accomplished. Down through the ages men have 
struggled, thought, studied, tortured, and bled to 
gain control of forces, that their children might have 
things of comfort. The American loves his New 
York, the Enghshman his London, the Frenchman his 
Paris; for in them he finds the things which satisfy. 
Late in the afternoon an observer upon the corner of 
one of the crowded thoroughfares of these great cities 
may find much of interest. The day is done. The 
workers (are not we all such?) hasten to the streets — 
the banker into the limousine; the clerk, after a pur- 
chase or two, into the bus, the underground, or the sub- 
way; the young bridegroom, with eager face — rushes 
off to take advantage of the fastest transport avail- 
able. Men go to the one place for which the things of 
life are created — home. Each carries with him things 
made in the industries which supply directly or in- 
directly products rendering life happy and comfort- 
able. So intent are we each day to leave business for 
home that we rarely stop to delve into the reasons for 
our possession of the necessary comforts of civiliza- 
tion. The sources of our food, the origin of our cloth- 
ing, even the roofs over our heads, are taken for 
granted. If the trolley fails to run, if the electric light 
goes out, we blame the public service corporation. A 
dead telephone may mean a late dinner; a blown-out 
tire requires hard work, and we in these days are too 



THE EVOLUTION OF AN INDUSTRY 5 

little used to it. The luxuries of yesterday have be- 
come the necessities of to-day, but they have come into 
use too rapidly to permit a real acquaintance. The 
things of rubber have become essential to the activi- 
ties of life because of the valuable services they ren- 
der. Without them our daily affairs would be strik- 
ingly different. 

The many enterprises which collectively compose 
the vast rubber industry rose from small beginnings 
in years so recent and into ramifications so numerous 
that our modern world may truly be said to be under 
the reign of rubber. The ruler of the realm is, in 
democratic fashion, the servant, not the master. The 
products serve, but do not dominate. 

The substance used to produce these various articles 
was made known to Europeans by the explorers of 
the Americas. When Columbus landed in the West 
Indies, he set men at work chopping trees. How our 
forefathers did love to chop trees! Certain of these 
trees oozed a white milk from the cut bark. Columbus 
remarked upon this. Later, in 1525, Spaniards in 
South America observed the natives playing with a 
ball made of a black substance, left when this milk was 
evaporated. Because of the wealth of unusual sub- 
stances brought back to Europe by these explorers, it 
is not singular, perhaps, that one of them, from the 
weeping tree, should have afforded nothing of value 
during more than two hundred years. 

The South American Indians went on with their 
ball play. Politics and wars absorbed the Europeans, 
until during the later eighteenth century samples of 
this weeping-tree product found their way into Eng- 



6 THE REIGN OF RUBBER 

land. Now, the Englishman has ever been a person 
of imagination, with zest to search out the new and un- 
usual. Therefore he studied the new American pro- 
duct in laboratory and office. With his commercial 
instinct, he placed pieces of it on sale. These 
attracted the attention of Dr. Joseph Priestley. This 
famous chemist, clergyman, teacher, author, who dis- 
covered ''dephlogisticated air," — afterward named 
oxygen, — wrote the following notice appended to the 
preface of his ''Familiar Introduction to the Theory 
and Practice of Perspective," printed in 1770: 
''Since this work was printed off, I have seen a sub- 
stance excellently adapted to the purpose of wiping 
from paper the marks of a black-lead pencil. It must, 
therefore, be of singular use to those who practise 
drawing. It is sold by Mr. Nairne, Mathematical In- 
strument Maker, opposite the Royal Exchange. He 
sells a cubical piece of about half an inch for three 
shillings ; and he says it will last several years. ' ' The 
French had called this substance caoutchouc, which 
was as close as they could come to caa o-chu, meaning 
"weeping tree." Priestley did not name it, but the 
men in the art shops christened it, in true colloquial 
English, "rubber" because it rubbed out pencil marks, 
and "Indian" because of its origin in the West Indies. 
But three shillings for a half of a cubic inch! It is 
the highest known recorded price for raw rubber. 
Would not our friends the ovmers of plantations rock 
with joy could they charge that price to-day when a 
bit less than two cubic inches brings but one cent? 

Ideas arise from observation of objects. Some men 
seej but do not gain thoughts or stimulus to imagina- 



THE EVOLUTION OF AN INDUSTRY 7 

tion from the things before them. Here was something 
new — a firm, elastic substance from a country of 
dreams. It was not soluble in water. Stories of cloth 
waterproofed by the milk poured on and dried, had 
filtered through to England and France. French chem- 
ists undertook the first chemical study of the material; 
for, as in the case of all our modern rubber and in- 
dustrial problems, research must ever precede produc- 
tion. And the play of genius in bringing forth ideas 
began. With characteristic energy, the English people 
went forward most actively. Exactly where, when, 
and how the first rubber factory 'of the world started 
seems to be in some dispute, although it is stated that 
in 1803 rubber thread for use in suspenders had been 
invented by an Austrian in the suburbs of St. Denis, 
near Paris. 

Whether the purpose was the making of thread to 
hold up the trousers of marikind or the making of 
water-proof garments, the first books on the rubber in- 
dustry do not seem to agree. We do know that the 
English were early the most successful manufacturers, 
and that the first practical articles were clothing and 
shoes. Many were the difficulties, uncertain the re- 
sults. 

The names of Charles Mackintosh and Thomas Han- 
cock are names ever to be remembered, because of 
their extreme activity in building up the industry. 
Discovering the solubility of rubber in various sol- 
vents and producing air-tight materials by ''proofing" 
fabric, they made pillows, air mattresses, and life-pre- 
servers. Although as early as 1791 the Englishman 
Samuel Peal had constructed waterproofed clothing 



8 THE EEIGN OF RUBBER 

with a single layer of fabric and a rubber layer on the 
outside, he made no success. In 1823, however, Mack- 
intosh overcame some of the difficulties. He invented 
what was known as double-texture clothing, and the 
* 'mackintosh" came into being. The mackintosh was 
popular among men who rode on top of the English 
coach. Things progressed swimmingly in England; 
Mackintosh's factory grew. Hancock was an inde- 
fatigable inventor. He went on with the making of 
hose, bumpers, carriage tires, and a large number of 
other products. Rain-coats were shipped to America. 
Rubber overshoes made on the Amazon River were 
sent to Europe and America. The first rubber to be 
imported into Boston was a rubber bottle from the 
Amazon. S. C. Smith & Sons of New York were the 
first firm in the business of dealing in rubber goods, 
and the Roxbury India Rubber Co. of Roxbury, Massa- 
chusetts, which was started in 1832 by John Haskins 
and Edward M. Chaffee, was the first to manufacture 
these rubber products in this country. Popular indeed 
were the rubber products. A rubber boom had begun. 

But there was a fly in the ointment; for this rub- 
ber, though water-proof and moldable into many 
shapes, possessed a basic fault. The rain-coats har- 
dened in cold weather, so that the poor consumer 
felt himself encased as in tin armor; in the summer 
the rubber softened with the heat, melted, and fell 
apart. 

Many efforts were made to dry up the rubber and 
prevent this stickiness and also to overcome the effect 
of oil and grease, but without success. So completely 
had rubber goods failed the American people because 



THE EVOLUTION OF AN INDUSTRY 9 

of warm summers and cold winters, that down to 
about 1840 they were filled with dislike for anything 
that related to ' ' gum elastic. ' ' People had become dis- 
gusted and rightly so with goods that hardened like a 
rock in winter and melted in summer. Even body 
temperature melted the threads in suspenders, and 
wearers of the celebrated mackintosh had to keep away 
from a fire or find their rain-coats oozing from them. 
The only reliable articles were Indian-made shoes 
from* the Amazon. Large quantities of clothing, 
mail-bags, and other water-proof articles melted, de- 
composed, and were returned. Therefore resentment 
followed favor, and the rubber bubble burst. 

Such conditions could not persist in connection 
with so flexible a substance. Men may come and 
companies go, but ideas grow in the minds of other 
men, who form new companies to carry on. Charles 
Goodyear, of New Haven, Connecticut, conceived it 
possible to dry up this sticky, melting, freezing ma- 
terial. Finally after years of effort, in 1839, he made 
a far-reaching discovery. He heated a mixture of 
sulphur, white lead, and raw rubber, and he observed 
a marked change of properties. This erstwhile soft- 
ish, doughy substance became firm, and strong; it no 
longer hardened in cold weather or melted in the 
summer. 

Even in the face of trials, failures, and discourage- 
ments, there are always a few men with vision enough 
to see and to support a new idea. So a factory was 
started in Springfield, Massachusetts, in 1841, to carry 
out Goodyear 's idea. Here began the real rubber in- 
dustry; for 'vulcanization, as this process of heating 



10 THE EEIGN OF RUBBER 

with sulphur was termed, is the one essential process 
even to-day. Without vulcanization, rubber as we 
know it would not be possible. 

A little later, in England, and by wholly different 
means of experiment, Thomas Hancock in 1843 dis- 
covered the same characteristic displayed by sulphur 
and rubber ; thus about simultaneously in England and 
America the modern manufacture of rubber goods be- 
gan. A complete change had been brought about by 
Goodyear — a basic process discovered. How he did it 
and what he did are left for a later chapter. Yet so 
fundamental was this effect, and so intense his activ- 
ity that for twenty-five years, from 1835, the history 
of the rubber industry is little else than the personal 
history of Charles Goodyear. An industry based 
upon a far-reaching idea now took shape. These en- 
terprises that men create measure their periods by 
ideas and grow with mankind, provided the products 
they offer render useful service. Rubber could now 
capably serve ; therefore growth was a natural conse- 
quence. 

It is strange how men strive to reap where others 
sowed. I shall not here discuss Goodyear 's troubles. 
Some men were pirates. His patent was infringed, 
but finally sustained. Then came many companies. 
Boots and shoes claimed almost exclusive attention of 
inventors and organizers for years. 

The first rubber overshoes delivered into this coun- 
try, in 1800, were made by the Indians on the banks of 
the Amazon River ; but to-day the old shoes have given 
way to the new, and we are protected from the weather 
by ** rubbers." Rubber boots have come to be a part 



THE EVOLUTION OF AN INDUSTRY, 11 

of the fisherman's outfit, and short ones are used by 
lumbermen; the liveliness of our tennis matches is in 
no small part due to the flexibility, lightness, and firm 
grip of the rubber-soled tennis-shoe. Through vulcan- 
ization, rain-coats have changed from tin armor in 
winter and the melted clothing in summer to a per- 
manent, light, flexible, water-proof, useful commodity. 

In 1858 the trade in rubber products amounted to 
between four and five miUion dollars annually, and 
ten thousand men were engaged in the enterprise. 
The Eoxbury company was reincorporated as the 
Goodyear Manufacturing Co., later to become, as it 
is still called, the Boston Belting Co. 

There were many keen men of high purpose and 
a few pirates. But some notable companies were 
formed, and many of them are still producing. Three 
great rubber manufacturing centers slowly developed. 
There was the New England district where Goodyear 
began, and the New Jersey centers where several foot- 
wear factories began. A number of these companies 
combined in 1892 to form the United States Rubber 
Co. The district of Akron, Ohio, began in an equally 
small way in 1870. The start resulted from the belief 
in rubber of Dr. B. F. Goodrich and the enterprise 
of the business men of the district. 

Were I at this point to trace the history of rubber 
goods development, the reader would observe a pro- 
fusion of inventions offered to the Patent Office; and, 
characteristically, many of them were ahead of their 
time. Ideas were written down, disclosed, or kept 
secret; but no use was found for them until decades 
later. 



12 THE EEIGN OF RUBBER 

Up to 1879, however, the industry strengthened; the 
value of the products amounted in that year to 
$25,310,000. It was truly an era of inventions and 
business development, for this chemical change called 
vulcanization had succeeded in making rubber suf- 
ficiently permanent to warrant labor by inventive gen- 
ius here and abroad in the creation of articles. 

In this period were developed the conveyor belts, 
which to-day are hundreds of feet long, serving to 
carry ore from crushers to furnaces for a large num- 
ber of different purposes. These, together with the 
elevator belts, have become as essential a part of 
mining operations as the crushing machinery used 
in reducing ore to a state ready for furnaces. Rubber 
has paralleled other inventions. To-day, in the trains 
which carry us from point to point rapidly and safely, 
we find rubber in the insulated wire for the lighting, 
in the air brake, and in the steam-hose between the 
cars themselves. 

The ''hose pipe" invented by Hancock in England to 
replace the old leather hose for breweries has come 
down to us through this creative stage, and now the 
fire-hose has become a most essential development. 
We might well stop to think what would happen when 
fire-engines go shrieking down the street if there 
were no vulcanized rubber in the hose so necessary in 
the distribution of water to the conflagration. Fire 
prevention is one thing ; but when a fire is started, hose 
that will not burst is an essential feature for rapid 
extinction. 

One need not run through a catalogue to show how 
these early ideas have been carried down and improved 



THE EVOLUTION OF AN INDUSTEY 13 

for our use ; that will be done with more detail in later 
chapters. I wish merely to anticipate and to mention, 
further, how large a part is played by rubber in sport, 
with its base-balls, golf -balls, tennis-balls, and billiard 
cushions; how in the home, floor-coverings, jar rings, 
garden-hose, fountain-pens, and other articles make 
life more comfortable. Even in 1899, these articles 
were so numerous that the indu'stry had grown to the 
stature of $49,212,000 in the value of products. 

In 'about that period began a noticeably rapid 
change. Since nothing has quite so greatly stimulated 
the imagination of business men as the possibilities of 
the automobile, there is no period of the rubber indus- 
try quite so filled with competition and with bubbles 
that have been blown and burst as the period from 1899 
to the present time. 

When you drive your automobile into the mountains, 
you give little attention to the part that rubber is play- 
ing in making your trip interesting and comfortable. 
If, however, a tire blows out and you are found fifteen 
miles from the nearest service station, you consider 
how necessary a commodity rubber has become at 
least to that particular expedition. 

The rubber-tire part of the industry is now a giant ; 
it serves to carry ten million automobiles upon forty 
million tires. Figures now astonish us, particularly 
as we look back and mark the change after even this 
short period of seventy-five years; for in 1914 the 
value of the products of the rubber industry had 
jumped to $300,994,000, and it produced in 1919 pro- 
ducts to the value of $1,138,216,000, made by 475 
factories. 



14 THE REIGN OF EUBBER 

This is the period of Akron's rapid advance. The 
enterprise of her business men expanded the B. F. 
Goodrich Co., and organized in 1898 the Goodyear Tire 
& Rubber Co., and in 1900 the Firestone Tire & Rub- 
ber Co., each of which has now grown to tremendous 
size, until into this city, to be used by over twenty 
rubber companies, comes more than one third of the 
total raw rubber consumed in the world. 

During these stages of development the industry pre- 
pared for the world war, into which it threw itself with 
whole-hearted abandon. It is strange how war reacts 
upon the soldier in the interests of a common cause. 
The sensitiveness and secretiveness of youth gave way 
before the broader views of maturity. Competitive 
strife disappeared ; the units of this maturing industry 
made balloons and compared notes upon the methods 
of construction. And it was rubber between two plies 
of thin fabric that held the hydrogen and kept the bal- 
loons aloft. Even in the big guns rubber gaskets were 
necessary in the recoil mechanism. The hospitals per- 
formed wonderful service, and rubber gloves, catheters, 
tubing, and water-bottles greatly assisted the skilled 
surgeons in the care of the wounded. Possibly the 
most notable service performed by rubber products 
lay in the gas-m*ask development — a romance in itself. 
The gas mask bids fair to become a defensive com- 
modity of the greatest moment in the future. 

You may find this industrial man not quite "the 
justice, in fair round belly with good capon lin'd," as 
after a large Thanksgiving dinner. We all enjoyed in 
the year 1919 the comfortable feeling of satiation. 
We have suffered the indigestion of youth from over- 



THE EVOLUTION OF AN INDUSTRY 15 

indulgence. Money flowed into buildings and mate- 
rials ; however, that stage of growth is happily passing. 
The factories are ably managed, they have survived 
the shock of depression, and they go forward to a 
greater service to mankind. 

The rubber industry is distinct in its principles of 
manufacture from any other. We are familiar with 
the metal group, such as steel and copper, in which 
chemical changes are brought about upon mineral ores, 
by "Which one substance at a time, such as iron, 
copper, or zinc, is produced. We know that each of 
them goes to the world in a variety of forms. This 
group is different from leather, for in that industry 
an animal product is altered by chemical change in a 
way that produces a tougher and more serviceable 
commodity, which later is worked up into a variety of 
forms. The manifold uses of cotton and the textiles 
come about from the mechanical purification of vege- 
table products and the weaving of them into sheets 
from which artisans create final forms without 
alteration of the substance which they modify. The 
great chemical industry, with its dye-stuffs, its caustic 
soda and sulphuric acid, its nitrogen products, begins 
its operations with two or more fundamental ma- 
terials ; and by the proper relations of time ; tempera- 
ture, and concentration it brings forth to us a great 
variety of new, different, and pure substances, each 
of which, as such, is used in a multitude of different 
ways. 

The rubber industry is peculiar in that it brings to- 
gether a large number of different animal, vegetable, 
mineral, and chemical materials. It chooses a num- 



16 THE EEIGN OF RUBBER 

ber of these to be scientifically acted upon mechanically 
to produce a mixture. It then forms those mechan- 
ical mixtures into the approximate shape of a new 
and useful commodity. This then is heated to bring 
about the chemical change, vulcanization. As a re- 
sult of vulcanization, each of these articles is capable 
of service. 

Since by common practice the word ''rubber" is not 
used in its original meaning, as describing th6 product 
from a tree, there has arisen a confusion in terminol- 
ogy. Most books and articles upon this subject have 
begun the story with a description of the preparation 
of the raw product, the early word for which techni- 
cally came from the Indian term for the tree: caa^ 
meaning wood, and o-chu, meaning to weep ; hence, the 
word ' ' caoutchouc. " It is probably the rapid growth 
of caoutchouc products, called rubber before the 
discovery of vulcanization, which has led to the con- 
fusion ; for to-day we speak of rubber products which 
have been vulcanized as "rubber." We also speak 
of rubber as meaning the raw unvulcanized mate- 
rial. Technically, therefore, ' ' caoutchouc ' ' means raw 
rubber; and "rubber" to-day means vulcanized rub- 
ber. Throughout this book the meaning will be evi- 
dent in each case. 

The rubber industry usually groups its products 
under the names : mechanical rubber goods, tires, foot- 
wear, clothing and proofed materials, druggists' 
sundries, and hard rubber. These classes will not be 
discussed, but rather the story will be written about 
certain particular ones, representative of the classes 
most frequently known and used. Each has a story 



THE EVOLUTION OP AN INDUSTRY 17 

of its own ; each is interwoven with a romantic history 
from the old days down to the present. 

Since raw rubber exists in a variety of forms and 
comes from a large number of different places in the 
world, since also its method of preparation and the 
story of its growth are chapters by themselves, since, 
likewise, vulcanization is the one fundamental proc- 
ess necessary to an understanding of the indus- 
try as^it now exists, I shall not follow the order of 
chronology, but plunge at once into a discussion of the 
fundamental processes which have made the rubber 
industry possible. This will give us a basis of un- 
derstanding, and the series of short stories of different 
rubber products will assume that the idea of vulcani- 
zation is known to the reader. 



CHAPTER II 

PROBLEMS OF A PIONEER 

Our eyes are holden that we cannot see the things that stare 
us in the face until the hour when the mind is ripened. 

— Emerson. 

The struggles of inventors in attempts so to change 
the properties of raw rubber as to avoid hardening in 
winter and softening in summer are truly the stories 
of men who burned their fingers without realizing that 
fire was the cause. Several of them were close to the 
solution of the problem, and yet they passed it by. 
Their failures make one believe that ''our eyes are 
holden that we cannot see" until discoveries may 
properly coordinate with others. 

A knife cut into the bark of certain evergreen tropi- 
cal trees permits a milky sap to flow. It looks like the 
juice of a milkweed or a dandelion. When it dries, 
there is left a brownish mass of a firm, tough substance. 
This is the same stuff that came to Priestley's labo- 
ratory and was called "Indian rubber." Frenchmen 
brought it to Europe, where many enterprising Eng- 
lishmen studied it and the great Faraday analyzed it. 
Germans experimented. Thomas Hancock writes in 
1856: "It is a singular fact that although this sub- 
stance had attracted the notice of chemists from the 
earliest date of its importation into Europe, they 

18 



PROBLEMS OF A PIONEER 19 

failed to discover any means of manufacturing it into 
solid masses or to facilitate its solution.'^ That is a 
damaging arraignment of chemistry, but we must re- 
member that the era of the chemical engineer had not 
arrived. In those days the chemist was an analyst 
whose chief aim in life was to find out what things 
were made of, not to develop their uses. 

The grand old man of rubber, Thomas Hancock, 
owned^a private laboratory. Not satisfied with a day 's 
work, he studied at home by night. He dissolved rub- 
ber in turpentine, and made many rubber articles. 
Charles Mackintosh, in 1823, at Glasgow, invented a 
process for spreading a rubber solution on two pieces 
of fabric and bringing them together under pressure ; 
he thus created the double-texture, water-proof gar- 
ment known even to-day as the mackintosh. Hancock 
developed a machine for softening raw rubber. He 
called it a "masticator," and his first experimental 
machine held one pound. He invented iron molds ; and, 
with a brick oven constructed by a bakery-oven builder, 
he formed blocks of rubber under heat and pressure. 
A little later, in 1822, he developed steam-heated ves- 
sels and, several years after, a masticator capable of 
holding two hundred pounds. It is fate that heat was 
used by him, and that a little later sulphur played its 
part, but that he did not connect the two. In his most 
interesting description called ''Personal Narrative of 
the Origin and Progress of the Caoutchouc or India- 
Rubber Manufacture in England," there were many 
difficulties and handicaps mentioned. 

Hancock, hoAvever, was a business man. Despite 
the losses and the worries suffered through the effect 



20 THE EEIGN OF RUBBER 

of light in decomposing the caoutchouc, he continued 
to invent new uses for rubber and patented them. He 
made artificial leather by a combination of cotton and 
other fibers in a rubber mixture. Much trouble was 
occasioned when the tailors sewed rubberized gar- 
ments together, for water crept through the holes 
made by the needles. Then, too, because the grease in 
the woolen cloth was absorbed into the raw rubber and 
destroyed it, many were returned. Hancock was for- 
tunate in living in England with its equable climate; 
for the heat was not great in summer, or was the 
cold severe in winter. Consequently, the numerous 
products from his real inventive genius did not seri- 
ously interrupt his profits. 

I have wondered why he did not employ a research 
laboratory. Although research in those days was not 
conceived of as in our generation, he was so far ahead 
of others that he might well have begun the practice. 
He may have reasoned, though, in the way many of our 
modern business men do, who seem to feel it advisable 
to reduce the appropriation for research laboratories 
during periods of depression. As a result, discoveries 
have been delayed and opportunities lost because of 
the lack of a little money expended for research at the 
right time. 

Hancock was on the verge of a great discovery, but 
he lacked just the necessary something possessed by 
another. While Hancock worked in England, there 
was some activity in America. In 1833, in consequence 
of goods returned because they had melted in the heat 
of summer, the Eoxbury India Rubber Co. was on the 
verge of dissolution. The firm had sent out products 



PROBLEMS OF A PIONEER 21 

with nothing done to prove their value except the test 
of actual service ; it has taken years to develop in the 
minds of men the fact that in fairness to the consumer 
tests of quality should precede sale. In the hot 
rains of August, rain-coats oozed rubber, while mail- 
bags fell apart, and letters were scattered. During 
zero weather the shoes sent from the Amazon became 
wooden, like the ''klomps" of Holland. An unreliable 
article was the suspender in those days ; perhaps that 
is why Americans came to prefer the belt to ''gal- 
luses." 

One day Charles Goodyear of New Haven, Connec- 
ticut, a man of thirty-three, passed by the New York 
store of the Roxbury company. He was not a busi- 
ness man, for he had failed in the hardware and farm 
implement business. He saw some life preservers. 
Because he could not help inventing, he designed a new 
one and returned a few months later to submit his 
sample to the clerk in the store. The clerk, wishing 
to do the enterprising Goodyear a service, confided to 
him the troubles of the Roxbury company. Placing 
a difficulty in the way of a genius creates the stimulus 
that ever has brought forth latent activity. Goodyear 
set to work. Cast into prison for debt, he shaped 
small test samples of raw rubber with a rolling-pin 
from the family kitchen. He mixed rubber with lamp- 
black, magnesia, and turpentine. With true research 
spirit, he submitted each of his mixtures to a weather- 
ing test in the open air. 

A ''presentiment of the future" spurred him on, 
until he became shabby and emaciated. His hands and 
clothing seemed to be covered continually with India 



22 THE EEIGN OF RUBBER 

rubber, and many of his friends tried to dissuade him 
by telling him that the India rubber business was now 
below par. At this time some one in New York was 
asked how he might recognize Mr. Goodyear. The re- 
ply was: "If you meet a man who has 051 an India 
rubber cap, stock, coat, vest, and shoes, with an India 
rubber purse without a cent of money in it, that is he. ' ' 
The friends who had backed him were ruined in the 
panic of 1836-37. By treating caoutchouc with nitric 
acid, he nearly suffocated himself in 1837. But 
nothing can stop genius. 

When the officials of the Roxbury company offered 
to help him with the use of the machinery at their 
plant, he removed to Roxbury. Although his inven- 
tive genius was used in the production of better ar- 
ticles, the thought of using sulphur did not occur un- 
til 1838, when he became acquainted with Nathaniel 
Hayward of Woburn, Massachusetts, who was the 
foreman of the factory of a rubber company that had 
just failed. Hayward was a practical man. He had 
approached the discovery of vulcanization, but he had 
not found it. His contribution to Goodyear was a 
process for partly hardening rubber by spreading a 
small quantity of sulphur over the surface of the raw 
rubber article. Then the mixture was put in the sun 
to dry. His patent, which was taken out in 1839, was 
purchased by Goodyear; and Goodyear used it in the 
manufacture of life-preservers. 

Goodyear was approaching the solution of the prob- 
lem that so far had seemed the doom of the rubber 
industry. Several different tales have been told, each 
of which sets forth the accidental nature of his great 



PROBLEMS OF A IPIONEER 23 

discovery. Possibly the best way to bring to light the 
truth is to let Goodyear himself explain ; this he does 
in that rare old book **Gum Elastic," published in 
1853. I shall not use his exact words throughout, but 
I shall quote him sufficiently to indicate the creative- 
ness of his mind and the research character of his ef- 
forts. 

He was on a visit to the factory at Woburn, where 
he had met Hayward. At the dwelling there where 
Goodyear resided, he made some experiments to as- 
certain the effect of heat upon the same compound 
that had decomposed in the mail-bags and other ar- 
ticles. He was surprised to find that the specimens, 
being carelessly brought in contact with a hot stove, 
charred like leather. He, however, directly inferred 
that if the process of charring could be stopped at the 
right point, it might divest the gum of its natural ad- 
hesiveness throughout, which would make it better 
than the native gum. He was further convinced of 
the correctness of this inference by finding that India 
rubber could not be melted by boiling in sulphur at 
any heat ever so great, but always charred. 

Other trials were made in which similar fabrics 
were heated before an open fire; and the same effect, 
that of charring, followed. *^ There were further and 
very satisfaci?ory indications of ultimate success in 
producing the desired results, as upon the edge of 
the charred portions of the fabric there appeared a line 
or border that was not charred but perfectly cured.'* 
With characteristic ability, he then tried other methods 
of heating, including steam. That this discovery of 
curing rubber was no accident, he himself makes 



24 THE REIGN OF EUBBER 

evident when he says: *' While the inventor admits 
that these discoveries were not the result of scientific 
chemical investigations, he is not willing to admit that 
they were the result of what is commonly termed ac- 
cident ; he claims them to be the -result of the closest 
application and observation." 

The discovery of rubber vulcanization was made in 
January, 1839. Possibly the season was fortunate, be- 
cause of the ease of performing heat tests near stoves 
on the inside and because of the severe cold for the 
weathering tests outside. But Goodyear had by no 
means finished ; for after his years of want and misery, 
discouragement and lack of support, he then went on 
to the next stage, that of convincing people of the value 
of his invention and of protecting it from the aggres- 
sions of those who now claimed that it was not his 
invention at all. 

Dr. Baekeland has well written: "I belie\se it was 
George Westinghouse who reminded us that every suc- 
cessful invention passes through three stages: The 
first, when it is said : ' Such a thing is absurd or im- 
possible.' The second stage, after the patent de- 
scriptions have become public and have given others 
the means to imitate and try to find loopholes in the 
patent claims, begins when it is said: 'The thing is 
not new.' And finally, after the usefulness of the in- 
vention has become so obvious and the details con- 
nected therewith have penetrated through the hard 
skulls of the laggards, then it sounds: 'There is no 
invention at all.' " 

So human inertia held back Goodyear : it was 1841 
before he convinced men with money, William Eider 




Courtesy of The B. F. Goodrich Co. 



A PHOTOMICROGRAPH OF SULPHUR CRYSTALS INSIDE A RUBBER 
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Courtesy of The B. F. Goodrich Co. 

Temperature Degrees Fahrenheit 

THE physicist's INTERPRETATION IN THE FORM OF CURVES OF THE RELATION BETWEEN 
HARDNESS AND TEMPERATURE, SHOWING THE STRIKING DIFFERENCE BETWEEN 
VULCANIZED AND UNVULCANIZED RUBBER 



PROBLEMS OF A PIONEER 25 

and "William DeForest of New York, of the value of Ms 
discovery. Shortly thereafter the factory from which 
the rubber industry in this country has sprung was 
started in Springfield, Massachusetts. Ever secre- 
tive, Groodyear was afraid of losing his rights; and 
while he obtained protection under a deposition of dis- 
covery in December, 1841, it was not until June, 1844, 
that the specification for his original patent was 
granted by the Patent Office at Washington. 

Meanwhile, he had sent to England a representative 
to learn if the secret could be sold to the rubber manu- 
facturers there. 

Thomas Hancock here takes up the story, in which 
he describes how in the early part of the autumn of 
1842 an assistant of his named Brockedon showed him 
some sample bits of rubber that had been brought 
over by a person from America. It was said that 
cold would not stiffen them and that they were not 
much affected by solvents, heat, or oils. But busi- 
ness men feared the idea of an inventor: the Mackin- 
tosh company told the agent that, as he could give no 
information, they could not judge of the merits of the 
invention and they were afraid that the product might 
not be capable of manufacture on a large scale, with- 
out a fresh outlay of money. Meanwhile, Brockedon, 
being interested in stoppers for beer-barrels, was im- 
pressed with the suggestion ; he gave samples to Han- 
cock, who at that very time was engaged in a study of 
methods by which rubber goods could be divested of 
their adhesiveness and made more permanent. 

Hancock took the usual industrial competitive point 
of view and set to work *'to match the competitor's 



26 THE REIGN OF RUBBER 

samples." Those of my readers who are chemists 
in the rubber business, will recognize this as one of 
the daily demands made upon them; they may be 
cheered in realizing how this system has been handed 
down from the early days. We rubber men are vic- 
tims of our circumstances; every one of us pulls, bites, 
and smells new samples. Hancock was no exception. 
He found in the samples strength, resistance to heat 
and cold, and a slight odor of sulphur. To solve the 
secret of the new compound, he heated raw rubber in 
molten sulphur. For a second time the sulphur- 
caoutchouc combination was effected by heat. Han- 
cock promptly patented his discovery in England in 
November, 1843. His assistant, Brockedon, termed 
the process '^ vulcanization." Thus, an American dis- 
covered the process ; an Englishman named it ; all the 
world has come to use it. 

Goodyear had made the short indispensable step in 
rubber manufacture; yet his discovery was the ob- 
jective of pirates, infringers, and guerrilla warfare. 
His claims, however, were sustained by litigation; 
Daniel Webster was his counsel, and Eufus Choate 
was the lawyer for the defendant. These legal con- 
troversies resulted in establishing clearly Goodyear 's 
priority and led to the extension of his patent for 
seven years from June, 1858. As Judge Grier, in giv- 
ing judgment in 1864, stated : * * Envy robs him of the 
honor, while speculators, swindlers, and pirates, rob 
him of the profits. Every unsuccessful experimenter 
who did, or did not, come very near making the dis- 
covery, now claims it. . . . Every man who has made 
experiments with India Rubber, sulphur, lead, or any 



PROBLEMS OF A PIONEER 27 

other substance; who has heated them in a stove or 
furnace; who has annoyed his family and his neigh- 
bors with sulphurous gas; who has set up a rubber 
factory and failed ; who has made India Rubber goods 
that no one would buy, or if bought, were returned as 
worthless, are now paraded forth as the inventors and 
discoverers of vulcanized India Rubber. . . . We are 
of the opinion, that the defendant has most signally 
failed in the attempt to show that himself, or any other 
person, discovered and perfected the process of manu- 
facturing vulcanized India Rubber before Charles 
Goodyear. ' ' 

Poor man, he died in New York in 1860 with debts 
of more than $191,000. A brilliant mind, a persis- 
tent worker he was, but a life of trouble was his. He 
was not a money-maker but an investigator. He never 
belonged to any of the so-called ''Goodyear compa- 
nies," or has any member of the Goodyear family 
since his death ever been in the rubber business. The 
name became a trademark. When his estate was fin- 
ally settled, the debts were paid and a comfortable 
fortune was left to his family. But, despite that, 
there ended pathetically one of the greatest names in 
inventive history. Emerson has written : ' ' Every 
action is measured by the depth of the sentiments from 
which it is produced." Goodyear 's persistence and 
his ability, the depth of his driving force, gave to the 
world the basis from which has sprung this tremen- 
dous industrial development of rubber. Thomas Han- 
cock, with that fairness so characteristic of the Eng- 
lish, acknowledged him to be the discoverer. 

Goodyear was a persistent investigator. He not 



28 THE EEIGN OF EUBBER 

only discovered the fact of the rubber- sulphur union 
with heat, but he developed the range of temperatures 
from 212° to 350° Fahrenheit, within which vulcan- 
ization can occur. Further, he observed the necessity 
for removing the material at the end of a suitable 
time. And to-day the properties of rubber obtained 
from vulcanization depend upon the amount of sul- 
phur and other substances in the mixture, the temper- 
ature at which the mixture is heated, and the time 
during which it remains under the influence of heat. 
The whole of rubber compounding practice, which will 
be discussed in another chapter, is purely one of 
adapting different materials, different amounts, dif- 
ferent times, and different temperatures to accomplish 
definitely sought properties. 

Sulphur is as important to the rubber industry as 
rubber. For while other substances have been found 
which, adding themselves to rubber, vulcanize it, sul- 
phur is the only one that combines cheapness with the 
ability to produce high qualities in the resultant vul- 
canized mixtures. 



CHAPTER III 
FUNDAMENTAL METHODS AND MACHINERY 

The entire rubber industry can be summed up thus ; 
It is the business of making and vulcanizing mixtures 
the chief ingredient of which is raw rubber. Cotton 
fabric is necessary to give strength and shape to par- 
ticular articles, but there would be no rubber goods 
without rubber mixtures. Mechanical processes serve 
to form the articles with speed and precision, but mix- 
ing is the fundamental process. Even were rubber 
and sulphur the only substances employed, it would be 
necessary to have machinery of some kind in order to 
incorporate this dry powder, sulphur, into the tough 
raw rubber. 

Rubber is a plastic; it is a body that when pushed 
does not break, but yields slowly. If a block of raw 
rubber is placed upon a table under a heavy weight, 
it gradually settles to a position of balance; that is, 
it settles until the resisting forces of the rubber coun- 
terbalance the downward pressure of the weight. 

This plastic nature of rubber makes it possible for 
us to mix substances into it. The earliest known 
machine used in any type of rubber manufacture was 
a mixer, called a ''pickle" by its inventor, Thomas 
Hancock, In his early days, about 1820, Hancock was 
engaged in the matter of elastic fastenings for gar- 
ments. He made springy stockings and elastic gloves. 

29 



30 THE EEIGN OF EUBBER 

In the course of his work, he accumulated considerable 
quantities of scraps. He also made elastic bands of 
rubber by cutting up small thin bottles imported from 
South America. These bottles had been made by 
evaporation of the latex upon forms. With the 
cuttings to save, Hancock cast about for some means gf 
forming them into uniform pieces. His first step was 
to procure a hollow punch an inch square and to cut 
out squares of rubber. He then tried pressing the 
pieces with a plunger in an iron mold. These ideas 
seeming not to succeed, he invented the first mixing 
machine. 

This machine was simply a hollow, round box of 
wood, with a crank for a handle and spikes upon a 
cylinder revolving between spikes in the wood about it. 
By these means, he was able to tear the rubber into 
small threads. If the cuttings were previously heated 
and the action was continued long enough, they 
gradually worked up into a homogeneous mass. See- 
ing the success of his experiment he went to a firm of 
machinery builders in England and had them make 
for him an iron machine of the same character. The 
improved apparatus he kept a deep secret until about 
1832. Continuously the active Hancock improved and 
developed this hollow cylinder affair, making it larger 
and larger and driving it by horse-power. The earlier 
name "pickle" was shortly changed to the more ex- 
pressive designation of masticator or masticating 
machine. The old pickle was slow. Hancock had one 
made to hold 180 to 200 pounds, but it did not mix dry 
powders and raw rubber with speed and accuracy. 

But let us go on to the processes of the modern 



METHODS AND MACHINERY 31 

rubber factory and follow them along. To-day raw 
rubber comes chiefly from plantations, clean and ready 
for the first step in the manufacturing operation. 
There are, though, scraps from the trees and ''wild" 
rubber from South America. These grades are dirty 
and wet. Therefore each factory needs a wash-room 
where the dirty raw rubber may be cleaned. The 
clean raw rubber needs only inspection. As each sheet 
is separated from the other sheets in the box, it is 
easily brushed free from any chips or foreign matter 
that may have been picked up in the course of trans- 
portation. 

Because the wash-room employs heavy machines, 
hot and cold water, and steam, it is a sloppy, wet, dirty 
department. The workmen, in rubber boots and 
aprons, throw the solid bales or lumps of crude rubbe-r 
into tanks, slightly to soften it with warm water. 
Then pulling apart the sheets of baled plantation rub- 
ber, they pass them between the two rolls of the wash- 
ing machine known as a cracker. The two steel rolls, 
placed horizontally and parallel to each other, are cor- 
rugated ; and they, to loosen the dirt, grind the sheets 
in contact with water. The washer, the next machine, 
has smaller corrugations cut into the rolls, which bite 
into the rubber and bring to the surface any foreign 
particles, which are washed out in the stream of water 
that constantly runs upon the mill. A step at a time, 
the sheet is corrugated more and more finely, or 
''creped," while new surfaces are exposed to the wash- 
ing action. 

There are several different kinds of washers, such 
as two-roll washers and three-roll washers, inclosed 



32 THE EEIGN OF RUBBER 

washers, tub washers, beater washers, and various 
others. But let us go along from the washing room to 
the next step, which consists in drying the rubber. 
Before any other sflibstance can be mixed with rubber, 
it must be dry. 

The wet sheets, which are probably one sixteenth to 
one eighth of an inch thick, about twenty-four inches 
wide, and vary in length from six to fifteen feet, 
are taken on trucks to the dry room. Several different 
methods of drying are used. In the old days, these 
sheets of rough-surfaced rubber were simply hung up 
in a room and allowed to dry over a period of time 
varying from two to six weeks, since raw rubber does 
not lose its water so rapidly as cotton cloth. They 
were never hung in the sunlight as we do clothing. In 
bright light, raw rubber oxidizes and spoils ; therefore 
the dry room must be dark and free from smoke and 
dust. Because inventors dislike any six-weeks long 
process, to speed up drying they forced the air in by 
fans and carried it out by exhaust. Six weeks dwin- 
dled to one. 

Then came a German invention, the vacuum cham- 
ber, into America, with still more rapid but safe drying. 
The vacuum apparatus is nothing but a metal chamber 
with hollow steam-heated shelves in it. The rubber is 
laid upon trays, slid in upon these shelves, and the 
door closed. By means of a powerful vacuum pump 
the air is exhausted. Steam is turned into the plates, 
and the rubber is heated to a much higher temperature 
than that used in the air drying rooms. In the 
presence of a vacuum, though, the danger of de- 
terioration by oxygen is avoided. The temperature 



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Courtesy of The B. F. Goodrich Co. 

* WASHING CRUDE RUBBER ON A WASHING MILL 




Courtesy of The B. F. Goodrich Co. 

A SPREADING MACHINE FOR COATING RUBBER CEMENT UPON CLOTH 




Courtesy of The Firestone Tire & Rubber Co. 

WEIGHING OUT COMPOUNDS IN THE COMPOUND ROOM OF A RUBBER FACTORY 



METHODS AND MACHINERY 33 

may now be raised considerably higher; and since 
water evaporates more rapidly in a vacuum than in the 
open air, the time required to remove the water from 
the rubber is reduced to two or three hours. 

But the vacuum drier did not seem wholly satis- 
factory for all types and kinds of rubber and for all 
purposes. In recent years, there has been another 
method that has entered into rubber manufacture, that 
of drying in the presence of moist air. It seems a bit 
singular to dry anything in wet air. Nevertheless, the 
method, with several systems of rooms in which rubber 
is placed on racks or trays, has been successfully used. 
The raw rubber dries in twenty-four hours. Really 
the air is only relatively wet. The water passes to the 
air because the air is drier. 

Many advocates of each of these systems of drying 
are found in the rubber industry. Each system is 
valuable for different types and grades of rubber 
to be used for various purposes. We are, however, 
here interested more in the fact that after the rubber 
comes out of the sloppy wash-room, it is dried before 
it goes into the next stage in the process of its manu- 
facture. 

Now our rubber, whether of one grade or several, is 
ready for the weighing-out of the mixture. Here we 
step into the holy of holies of the rubber factory. 
From the beginning of the industry, rubber plants have 
carefully guarded the composition of their mixtures; 
they are the recipes of the business. Each one of 
them is made for a particular purpose. Since every 
rubber factory is convinced that its own formulas are 
better than the formulas of any other, each guards its 



34 THE EEIGN OF EUBBER 

recipes as something sacred. So careful are they, 
that the recipe, as it issues from the laboratory to this 
weighing-out or compounding room, must needs be 
divided up into different parts by the chief compounder 
or confidential man. The grades and quality of rubber 
to be used are written on one card, the dry pigments on 
another, the reclaimed rubbers on still another, and 
the sulphur on a last one. 

In the compounding room the final work of the 
chemists really comes into play. In this part of the 
factory great accuracy is required. To be sure, if the 
manufacturer happens to be a rubber man of the old 
school, he may call his chemist into the private office 
and tell him how in the early days there were no 
chemists and no laboratories. He may even try to 
convince him that powders were measured by the 
bucket and rubber by the yardstick. But because the 
demands made upon rubber goods have become more 
and more exact, greater accuracy is required at the 
present time. 

Care is necessary in preparing these various sub- 
stances other than crude rubber. The dry pigments 
must be sifted through fine silk screens free from 
foreign ingredients. The coarse particles, the chips 
from the bales, or any other accidental substances are 
thrown into the scrap-heap. The compounding room 
is one of the places in the rubber factory where purity 
of substance is accomplished. Obviously, there would 
be tremendous irregularities in rubber composition 
were the scales not exact upon which these substances 
are weighed. At regular intervals, standard weights 
are taken about the compounding room; and each set 



METHODS AND MACHINERY 35 

of scales is adjusted. Although there have been some 
efforts made to develop automatic scales to weigh the 
right quantity of a single substance for each of a large 
number of batches, up to the present time none of them 
seems to have come into sufficient use to warrant its 
being considered as accurate or reliable. 

In the best of the compound rooms, the powders, 
after sifting, are automatically dropped through the 
floor into metal hoppers, each containing its own 
particular pigment. From these bins, which are 
placed side by side, the operator weighs out the proper 
ingredients. Conveyor systems are used for handling 
the boxes, so that the pigment boxes and the rubber 
boxes move systematically from one end of the room 
to the other, each receiving the correct quantity of the 
right substances. When these various substances are 
accurately weighed and placed in their respective 
boxes, they are conveyed down to the mixing room, or, 
as the rubber man terms it, the mill-room. 

We speak of the masticator, the mixer, or the mill. 
By common consent, a rubber mill is considered to be 
that particular piece of machinery upon which the va- 
rious ingredients of a compound are mixed together 
in form for the next step in the operation. Edwin 
M. Chaffee, one of the pioneers of the American rub- 
ber industry and a co-worker with Charles Goodyear, 
was the inventor, in 1836, of the first iron-roll, steam- 
heated rubber mixer. It was a different machine from 
Hancock 's, for Hancock kept his rubber inside a cham- 
ber. Chaffee had his rubber outside, but in such 
fashion that it was compressed between two 
rollers. From the original Chaffee mixer to the mod- 



36 THE EEIGN OF RUBBER 

ern mixing machine is not a great step in fundamen- 
tal principle, and Chaffee may be considered the 
father of rubber factory machinery. 

Of different sizes, the largest of these machines to- 
day consists of two mixing rolls, twenty-four inches 
in diameter and eighty-four inches long, set in a heavy 
frame, and made from either chilled or dry sand iron. 
One roll has a driving gear operated by a pinion on 
the shaft underneath, on one side. On the other end 
of the drive-roll is a gear which meshes into another 
gear on the end of the front roll. These gears are of 
different sizes, to give friction or different speeds to 
the rolls, so that there is a wiping action upon the 
rubber as it passes between them. This wiping action 
seems to be efficient in forcing the dry powders into the 
plastic rubber. Set beneath each of the mixers is a 
metal pan; for when the rubber is being masticated 
and mixed, not all of the dry pigments remain on top 
or go immediately into the rubber. A good deal falls 
through into the pan; and the operator, with a brush 
and a shovel, gathers this up and shovels it from time 
to time to the top of the mill. 

Let us go down into the mixing room and see hcfw 
a batch of material is mixed. Stand in front of this 
piece of machinery. The speed of the rollers is not 
high, — only a matter of fifteen to twenty revolutions 
a minute, — ^but one gets the impression of great power". 
Our operator, standing in front of his mill, picks the 
rubber out of the boxes ; and, placing it in position on 
the upper side of the moving rolls, pushes it so that 
it is caught and drawn in between them. "With a 
powerful action, with grinding and screeching, with 



METHODS AND MACHINEEY a? 

the bursting of little blisters as they form, the 
rubber is carried between these two rolls and broken 
up into various large chunks. An automatic mechan- 
ism known as an '' apron '^ brings the rubber that 
falls between the rolls up again to the top, where the 
operator pushes it once more over into the space be- 
tween them. He is protected against accident by an 
automatic tripper. If he leans his hand against the 
tripper, the motor will be disconnected from the mill 
and tlTe resistance of the several mills on the same 
shaft will cause them all to stop. So our workman, 
without danger, protected by the best of safety de- 
vices, continues to see that the tough, cold rubber is 
sent back through the rolls. 

You observe how the rubber gradually softens; it 
begins to smooth out in spots. The noise and creaking 
of it subsides, until, after ten or twelve minutes, it is 
smooth and clings to one of the rolls sufficiently so 
that it goes around in the form of a sheet the thick- 
ness of the space between the rolls, usually about three 
quarters of an inch. A little excess of rubber known 
as a *'bank" stands on the top between the rollers. 

Then the rubber is masticated. It has been softened 
by the friction developed by the two rolls running at 
different speeds, by the heat generated, and by the 
mechanical working. When it is thus softened, it is 
ready to have the dry pigments added. The operator 
now shovels the dry pigments from the compound box, 
in which the mixture was brought down from the com- 
pounding room, upon the upper parts of the rolls. 
Some day all rubber mixing apparatus will be equipped 
with automatic mixers. The Workman shovels the 



38 THE EEIGN OF RUBBER 

other substances upon the rubber, without knowing 
what they are, where they came from, or their quan- 
tities. Quickly the masticated rubber, as it comes 
around, catches up a coat of dry pigments. Since it 
takes a little time for the rubber to absorb these sub- 
stances, much of the pigments slips through and is not 
pressed into the rubber. 

Rubber is a peculiar material; it cannot be quickly 
forced as machines can force brass or steel; it yields, 
and then returns to its original position. It seems to 
have a temperament ; it can be guided, but only slowly 
driven. Therefore the workman shovels on the pig- 
ments at about the rate that the rubber wishes to eat 
them up. The sheet on the rollers looks streaked and 
irregular. After five or ten minutes more have 
elapsed, though, all the dry pigments will have dis- 
appeared ; but the rubber still seems grainy, like wood. 
At this point it is probably in its most critical state, 
so far as uniformity is concerned. If this batch 
in its present condition were to be taken from the mill, 
it could not yield a product of good quality. There 
would be more powder in one part of it than another. 
The sulphur would probably be concentrated at 
one end. 

The workman is obliged now to perform the final 
but most necessary operation, that of true mixing, 
which he does by what we call "cutting back and 
forth." With a sharp knife and the skill born of ex- 
perience, he cuts his rotating, thick, slow-moving sheet 
of rubber, so that a long strip probably a foot wide is 
removed from one end of the roll. This strip he 
quickly throws over across the roll; thus he transfers 



METHODS AND MACHINEEY 39 

a portion of the rubber from one end over to the other 
end. When that has passed around, he cuts from the 
other end a similar long strip and throws it back in the 
opposite direction. In this way, different parts of the 
batch are removed from the places where they were 
and are put in contact with rubber in other parts of 
the batch. 

The operator is now a busy man, for he cuts and 
throws these big ribbons over against the sheet. Back 
and f(5rth, back and forth, on a large-scale operation, 
he acts as the druggist when he mixes his pill powders, 
or the housewife when she mixes bread; he inter- 
mingles all parts of the batch. The rubber is now 
soft and hot. Temperatures of 180° to 200° Faren- 
heit are generated by the heat of friction, despite the 
fact that a stream of cold water is forced into the 
hollow cavity of these rolls for the express purpose of 
regulating the temperature of the mixture. So high 
is the heat of friction that if the rolls were not cooled, 
the composition would partly vulcanize while mixing. 
We call this ''semi- vulcanization'^ or ''scorching." 
Because the mill-room operators must constantly 
guard against scorching, cold water has come to be a 
necessity in the rubber industry. I do not mean ice- 
cold water. That would be too cold. In the econom- 
ics of the rubber industry, the location of a rubber 
factory where good, cool, water, and plenty of it, is 
found, is as fundamental as that of a location upon a 
railroad. . 

The technique of mixing is varied; it is one of the 
skilled operations of the rubber industry, compositions 
of different character requiring variation in handling ; 



40 THE REIGN OF EUBBER 

and the temperature of some naturally rising higher 
than that of others. It is interesting to those who fol- 
low the details of the history of the rubber industry to 
observe how within the last few years inclosed mixing 
machines have gradually come back into use. The 
first Hancock masticator was an internal machine, 
and the Chaffee was made on the external principle. 
In a limited way, we now again mix in chambers by 
the internal action of the rotating parts; this action 
softens the rubber by working it against the side of 
the shell that incloses it. 

When our workman is finally satisfied that the rub- 
ber is thoroughly mixed with the pigments, his next 
step is to remove it from the mixing machine. This 
he does by cutting a large sheet from the masticator 
as it rotates in front of him; he then throws it by a 
quick movement upon a cooling-table. Here it is al- 
lowed to stand for an hour or two until it is cooled 
sufficiently to avoid a scorching tendency. From this 
place, it is transported to the storage room, or into 
the factory where the next operation is performed. 

It we take a trip around the plant, we logically go 
from the mixing room to the department where the 
rubber is made ready for the forming operation. In 
the old days, the mixed rubber was dissolved and 
then applied upon fabric by means of a spreading 
machine. This machine was constructed to permit a 
sheet of cloth to pass over a rotating cylinder, above 
which hung a flat metal bar called a knife or doctor 
blade. The blade was accurately adjustable. So close 
could it be set to the fabric that it permitted only a thin 
film of solution to pass between it and the fabric. 



METHODS AND MACHINERY 41 

Thus a thin layer of rubber cement could be applied to 
cloth. 

One day in 1835, Mr. Chaffee went to the directors 
of the Roxbury company, saying he could save them 
the expense of the solvent that they had been using 
by the old process, which, by the way, cost them about 
fifty thousand dollars a year. He was instructed to 
build the necessary machinery. The invention of the 
calender machine resulted. 

His 'coating machine was called the ** monster" or 
the ''mammoth," on account of its dimensions. It 
weighed about thirty tons, and was finished toward the 
end of the year 1836 at a cost of thirty thousand dol- 
lars. The Roxbury India Rubber factory purchased 
from Mr. Chaffee his entire interest in the ''monster." 
But during the month of October, 1843, the huge ma- 
chine was sold at a public auction for only $525 to John 
Haskins, who at the same time purchased a patent on 
it for $1.50! During the year following, 1844, Has- 
kins disposed of the "monster" to Charles Goodyear, 
who later transferred it to the Naugatuck India Rub- 
ber Co. 

A calender is simply a machine with three or more 
heavy steel rolls set parallel to each other, in such a 
way that when the soft, warm, unvulcanized rubber 
mixture is fed against the space between two of the 
rolls it will be forced between them in a thin sheet. 
This is called a sheeting calender. Likewise, when it 
is desired to apply rubber to cloth, cloth is drawn be- 
tween the rolls, which are separated far enough so as 
in no way to crush the fabric, and which push the soft 
rubber into and around the threads. This is termed 



42 THE EEIGN OF RUBBER 

a ''friction calender/' and the operation ''friction- 
ing." In the parlance of the trade, we speak of the 
compound as the ''friction" and the cloth as "fric- 
tioned fabric." In other machines, the cloth, after 
f rictioning, can have a coat or layer of rubber applied 
upon it. For tire fabric purposes, we are accustomed 
to speak of "friction and coated fabric," or "friction 
and skin coat. ' ' 

If in the calender room we stand in front of one of 
these machines, which are from seven to ten feet high, 
we find masses of rubber compound, as they run from 
the rolls, taking the shape of sheets. To keep them 
from sticking to each other, they are wound up with 
cloth or "liners" to separate them. The sheets issue 
from the machines at considerable speed, and are 
whirled into rolls, which are carried to the various 
other parts of the factory on hand-pushed or electric 
trucks. 

Many other machines are employed to make particu- 
lar articles in the rubber industry, but those described 
are the essential ones. 

The manufacture of rubber goods may be likened 
to a tree. Thousands of materials — raw rubber, 
powders, sulphur — are the roots. These are combined 
in the trunk, through a few basic methods. The mill- 
room, where mixing is done ; the calender room, where 
the first process of forming is accomplished, are the 
steps essential to manufacture. The final step of 
forming and, last of all, vulcanization, are carried on 
in the several divisions of the factory within which 
the special articles are produced. They are the 
branches of our tree. 



METHODS AND MACHINERY 43 

Eubber mixtures are the basic materials ; the chem- 
ist formulates them; cotton cloth and these mixtures 
are put together in forms and shapes by the design- 
ing engineer who creates articles ; and, to manufacture 
them expeditiously and uniformly, the inventor and 
production engineer must invent and use many kinds 
of machinery. The rubber industry, therefore, stands 
on three legs ; the mixture, the design, and the machine 
— each essential. 



CHAPTER IV 
THE RUBBER MAN'S COOK-BOOK 

Oh, I am a cook and a captain bold, 

And the mate of the Nancy brig, 
And a bo 'sun tight, and a midshipmite, 

And the crew of the captain 's gig. 

—Gilbert: "The Yarn of the Nancy Bell." 

The old-fashioned rubber superintendent was a ver- 
satile chap. From dawn on, there came to him for de- 
cision essentially all the manifold problems of the 
rubber factory. Personally he selected the laboring 
men ; he was the power engineer, and if the coal was 
bad, it was his duty to keep the plant running. He fig- 
ured costs and made prices. A chemist also, he wrote 
the formulas or recipes for the various mixtures used 
in the goods manfactured. He was even the first-aid 
doctor; since in the early days machinery was not 
surrounded by the safeguards that we find to-day, and 
many a man whose hand was caught in the mixing 
mill was carried to the superintendent's oflfioe for 
first-aid dressing. In many cases, he was a salesman ; 
and he certainly was the production driver. As both 
an inventor and a promoter, he labored. Truly those 
were strenuous days for the superintendent. 

I once talked to one of those men, long since retired 
from active participation in rubber factory work. He 

44 



THE EUBBER MAN'S COOK-BOOK 45 

told me how the mixtures of rubber, which we call by 
the name of "compound," were studied in his office. 
By means of a little piece cut from a sheet with a pair 
of shears, he tested the quality. This fragment he 
twisted, pulled, and worked in his fingers. Finally al- 
lowing it to come to rest, he examined it, to see how 
much longer it was than the original piece from which 
it was cut. The ease of pulling, the ''feel," and the 
additional length were prime factors in determining 
the qifality of a particular mixture. Even teeth were 
trained to bite pieces from a specimen, the resistance 
to the bite being a measure of its strength. A testing 
laboratory was ever with him in the form of fingers 
and teeth. 

Those old formulas were clouded with secrecy. In 
the compounding room were employed only most re- 
liable men, known for honesty and loyalty. A recipe 
was a great secret of master importance. Before long, 
however, ambitious youths came to realize that qual- 
ity as produced by good formulas was the basic prin- 
ciple on which the success of a given rubber plant was 
built. Therefore many of them left, taking with them 
the secrets ; and competition rapidly grew. 

To-day, with the coming of the chemist, a different 
tone has been given the industry; no longer does the 
rule of thumb method apply. No longer is it neces- 
sary for competing institutions to worry much about 
the compositions used in the factories of each other. 
There has come in these recent years a fuller under- 
standing of why various materials act in particular 
ways when used in rubber mixtures. The chemist, 
the physicist, and the engineer have brought real 



46 THE EEIGN OF EUBBER 

knowledge into rubber making. To promote such 
knowledge, each of the larger rubber companies has 
organized laboratories, in which highly trained chem- 
ists stndy new materials and, as a basic function of 
such study, learn how each material performs in a 
rubber mixture. There are testing laboratories, too, 
where each rubber composition may be studied and 
where each new product may be tested in terms of 
actual service. 

The rubber that you see in the form of a rubber 
band, the heel that you wear upon your shoe, or the 
tread of a pneumatic tire, is not just a simple vulcan- 
ized mixture of rubber and sulphur or is it so simple 
a composition as the combination of rubber, sulphur, 
and white lead used by Goodyear. The compositions 
are much more complicated than they formerly were. 
In the course of the evolution of this industry has come 
a revised point of view, so that to-day each substance 
used in a mixture is there for a particular purpose. 

The field of substances from which the rubber chem- 
ist chooses those for any desired compound is ex- 
tensive. In one of the large rubber factories, five 
hundred raw materials, known as pigments are used. 
Pigments are dried powders, such as zinc oxide, lith- 
arge, whiting, barytes, clay in various types, car- 
bon black from natural gas, and so on through the long 
list. Even crude rubber has ceased to be -of one or 
two grades. It has become fifty different types, with 
different sources, methods of preparation, degrees of 
hardness, physical properties, and workability. The 
factories use between fifty and one hundred grades 
known as reclaimed rubber, which is the result of proc- 



THE RUBBER MAN'S COOK-BOOK 47 

essing previously vulcanized rubber products that 
have ceased to perform their usefulness-^scrap tires;, 
old shoes, and the like. 

The rubber chemist, therefore, has come to know in- 
timately many thousands of materials. Like a good 
cook, he must understand by experience what each 
one will do in his mixtures; and, like a highly scien- 
tific investigator, he must know accurately if the re- 
sults will be worthy of production and sale. In the 
refinement of his business, he has become, therefore, a 
sort of highly sublimated chef; and his formula books 
are the cook-books of rubber. 

Let us follow the work of the rubber chemist. He 
operates quite differently from the cook in the home ; 
for, if she has something new to make, she works it 
out in the form of a real mixture on the kitchen table, 
putting in a pinch of this and a little of that, using her 
experience as a guide. In the rubber laboratories, 
systems have been developed so that the chemist does 
not himself weigh out his mixings ; instead, he writes 
his formula or recipe in his office. Here are his books 
of reference, his samples of raw materials. If we fol- 
low the formula written by this chemist from his office 
through the various changes of its manufacture and 
test, we shall go to a laboratory, in which are little 
machines the same in principle as those in the great 
factory. Here we obtain the fundamental informa- 
tion that is expressed on larger scales in tires, shoes, 
and other articles. 

Our chemist may show us how he would make an i 
inner tube for an automobile tire. Inner tubes must i 
hold air, and be soft and flexible. They must stretch 



48 THE REIGN OF RUBBER 

with relative ease without tearing. A typical formula 
would probably be: rubber of the highest grade, one 
hundred parts by weight; sulphur powder, five parts 
by weight; zinc oxide, three parts by weight; and an 
accelerator such as hexamethylenetetramine or, as the 
doctor knows it, urotropin, one half of one part by 
weight. Written on a card, this formula is sent into 
the laboratory compounding room. In this room 
works the reliable old employee, who accurately weighs 
these ingredients and places them in a tin box that is 
carried out into a rorom where operate a number of 
little mills, calenders, and vulcanizers. 

Were our formula to be mixed on the full factory 
scale, it would have appeared, before that process, very 
much as it does in the photograph. 

For purpose of test, it is customary in the laboratory 
to vulcanize such a compound in the form of a sheet. 
In the photograph of the hydraulic press you will no- 
tice two flat plates or platens with a little table at- 
tached to the lower one ; this is moved up and down by 
hydraulic pressure. Upon the table lies a mold, which 
is, in point of fact, a simple metal frame, made to re- 
tain within a definite length, width, and thickness the 
rubber to be vulcanized. The workman removes the 
rubber from the mixing mill for testing purposes in 
the form of a sheet of fixed thickness a little more than 
that required in the mold. After he places the cover 
upon it and slides it in between the two press plates, 
he turns on the hydraulic pressure; then the mold is 
squeezed, and the soft rubber compound fills the 
cavity of the mold. Rubber, being a soft plastic 
and flomng slowly under pressure, is not melted as 




Courtesy of J. P. Devine Co. 

DRYING RUBBER IN THE VACUUM DRYER 




Courtesy of The Hunter Dry Kiln Co. 

DRYING RUBBER IN THE AIR DRYER 



THE RUBBER MAN'S COOK-BOOK 49 

iron is melted when cast into various shapes in the 
foundry. If we were to try to melt it, a useless prod- 
uct would result. In the mold there is always a little 
extra volume of rubber, which flows out into grooves 
and which we call the overflow, rind, or flash. This 
overflow insures uniformity of pressure and vulcan- 
ization in a solid, unblemished piece. 

To furnish heat, steam is passed through the hollow 
platens or the plates of the press. The particular 
composition that we are discussing would probably 
vulcanize in forty-five minutes, with press plates at 
a temperature of 290° Fahrenheit. To be sure, an 
inner tube would not be cured between plates in this 
way; the formation of a tube we shall discuss in 
another part of the book. In performing a test to de- 
termine the properties of this composition after vul- 
canization, the chemist would not simply pull it by 
hand, as the old-time superintendent did. He might, it 
is true, observe differences in the amount of force 
necessary to pull out such a piece a definite distance; 
but such a test would not give data accurate enough 
to distinguish between compositions of various kinds, 
with materials in different proportions. Therefore 
the rubber chemist, after removing the vulcanized 
rind, takes his cured piece into the testing laboratory. 

Here are machines and apparatus designed partic- 
ularly to test rubber. Since rubber stretches to a 
greater degree than any other known substance, we 
must allow for length of pull in our test machin- 
ery. Steel stretches but fractions of inches before it 
breaks; rubber, six, eight, to ten times its original 
length. It thins down as it elongates. Specially made 



50 THE EEIGN OF EUBBER 

jaws automatically contract against the piece of rub- 
ber to be tested and prevent it from slipping out. 

Let us watch the test piece in the laboratory. On 
the machine there is a dial to indicate the number of 
pounds required to pull the piece a definite distance. 
The operator marks lines two inches apart upon the 
piece. When the rubber breaks, the distance of sep- 
aration of these two marks gives him a definite figure 
that he calls elongation, or stretch. 

Of late years, the chemist has -been accustomed to 
draw a picture of the course of this testing. As you 
stand in front of the machine, you will notice at once 
that the rubber piece stretches considerably with but 
little increase in the number of pounds indicated on 
the dial or the chart ; but that after it has stretched a 
considerable distance, it resists more and more fur- 
ther distortion. The little picture being drawn will 
show us the force required to do the stretching. 
Known to the chemist as the "stress-strain," or 
**force-stretch" curve, it portrays the relation inch 
by inch between the elongation of the rubber and the 
force producing it. Thus rubber writes its own auto- 
biography, from the reading of which our rubber chem- 
ist is able to determine a good deal of its value ; he is 
able to determine particularly the differences in the 
values of substances to be used in the mixings. 

In the formula an "accelerator" is used. Let us 
concentrate our attention upon this substance for a 
moment. Charles Goodyear might not have succeeded 
in taming rubber had he not used in his mixture a 
mineral powder known as white lead. Without white 
lead, the mixture would have taken so much longer a 




A WEIGHED-OUT RUBBER MIXTURE CONTAINING 100 PARTS RUBBER, 8 PARTS SULPHUR 




A WEIGHED-OUT RUBBER MIXTURE CONTAINING RUBBER 100 PARTS, ZINC OXIDE 3 PARTS, 
SULPHUR 5 PARTS, HEXAMETHYLENETETRAMINE I PART 




A WEIGHED-OUT RUBBER MIXTURE CONTAINING RUBBER 100 PARTS, ZINC OXIDE 100 PARTS, 
SULPHUR 5 PARTS, HEXAMETHYLENETETRAMINE I PART 




Courtesy of The B. F. Goodrich Co. 

A WEIGHED-OUT RUBBER MIXTURE CONTAINING RUBBER 100 PARTS, GAS BLACK 35 PARTS, 
ZINC OXIDE 3 PARTS, SULPHUR 5 PARTS, HEXAMETHYLENETETRAMINE I PART 



THE RUBBER MAN'S COOK-BOOK 51 

time to vulcanize that he might not have observed, at 
least so quickly as he did, the change in the properties 
of the rubber. Because white lead when used in a 
rubber mixture shortens the time of vulcanization, we 
call it an accelerator. The combination of raw rubber 









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O •400 eoo isloo looo sooo 2400 zooo 3ZOO d«oo 4oeo 

TENS1l.e STRENGTH IN POUNDS PER SQUARE INCH 

Courtesy of The B. F. Goodrich Co. 

THE AUTOBIOOEAPHY Or THE FOUR EUBBEB COMPOUNDS MENTIONED IN THE 

TEXT 

and sulphur by themselves would require several 
hours under heat before enough sulphur would be com- 
bined to give snappiness and the other properties of 
vulcanized rubber. "When white lead is used with the 
rubber and sulphur, however, this time is reduced 



52 THE EEIGJM OF RUBBER 

to a short period. It happens in this particular case 
that white lead itself changes in the presence of sul- 
phur from a white to a black substance because, as the 
chemist will tell us, of the formation of lead sulphide, 
which is black. 

These accelerators seem to serve as stimulants to 
the combination of sulphur and rubber, just as when 
you place your foot on the accelerator of your automo- 
bile, you permit more gas to flow into the cylinders, 
and your automobile increases its speed. In a like 
manner, when accelerators are used in the rubber mix- 
ture, a more rapid flow or combination of sulphur with 
the rubber takes place. In the chemical world they are 
called * * catalysts, ' ^ and they are widely used in chem- 
ical processes. The making of sulphuric acid re- 
quires the use of catalysts in order that the combina- 
tion of sulphur dioxide and oxygen may take place not 
only within reasonable lengths of time, but with suf- 
ficient completeness to make the process one of com- 
mercial value. In the rubber process, the catalysts 
themselves change somewhat; yet the definition 
is broad enough to include any substance which facil- 
itates the course of vulcanization. The first cat- 
alyst, or accelerator, was the white lead used by Good- 
year. For many years only such mineral substances 
were used. Litharge or lead oxide aided in making 
many of the best tires produced in this country. Lime, 
magnesium oxide, and others have been and still are 
common in rubber manufacturing practice. 

Within the last few years publications have been 
setting forth the details of this ultra-secret phase of 
rubber compounding. The better-trained chemists 




Courtesy of The Firestone Tire & Rubber Co. 

MIXING RUBBER COMPOUNDS IN THE MILL ROOM 





Courtesy of The Firestone Tire & Rubber Co. 

FRICTIONING CLOTH WITH UNVULCANIZED RUBBER MIX- 
TURES ON THE CALENDER 



HANCOCK S PICKLE. INVENTED 
IN 1820. TAKEN FROM "PER- 
SONAL narrative" by THOMAS 
HANCOCK 



THE RUBBER MAN'S COOK-BOOK 53 

have come to use synthetic organic chemicals as accel- 
erators, for they have found them remarkable in 
powers of action and in giving a quality to rubber mix- 
tures that had not been dreamed of before. The 
organic compounds are, in the majority of cases, pro- 
ducts derived from chemical processes upon coal-tar. 
They are related to the organic dyes, many of which 
are good accelerators. Some of them are drugs, the 
one used in this formula being of that type. Only a 
small "Amount of these organic accelerators is neces- 
sary. Of the old inorganic, or mineral, ones, such as 
white lead, formulas required from 5 to 15 per cent, by 
weight; these new substances employed so largely in 
later years, however, require less than 1 per cent, to 
give even more active acceleration. They seem also 
to increase the strength of the rubber and its resist- 
ance to abrasion, to heat, and to oxidation and aging. 
The discovery and first use of the organic accelerator 
was nearly as great a step forward as that of vulcan- 
ization. 

To make history reliable, one must mention at this 
point the name of a most able man of the younger 
generation, Mr. Arthur H. Marks, and his assistant, 
Mr. George Oenslager. To them goes the credit for 
the first introduction of a typical organic accelerator 
in commercial rubber manufacturing practice. In 1906 
the records of the Diamond Rubber Co., of Akron, 
Ohio, later combined with the B. P. Goodrich Co., show 
that they first employed aniline oil as an accelerator 
of vulcanization. Because of its poison-ous nature, 
this substance had one disadvantage. It is quite nat- 
ural, once Mr. Mark's mind turned in this direction, 



54 THE REIGN OF EUBBER 

to find him making every effort to determine the prop- 
erties of other organic substances that might vulcan- 
ize rubber with equal speed, furnish equal strengthen- 
ing properties, and be free from poisonous character- 
istics. This was too secret a matter to permit of pub- 
lication. As a result, these men have up to now never 
received public credit for this tremendously potent 
advance step in rubber manufacture. In 1912, how- 
ever, some Germans patented in this country a con- 
siderable number of organic substances for this pur- 
pose. Once these disclosures were made, chemists in 
the rubber business went ahead with great strides, 
until to-day there are a large number of organic ac- 
celerators in current use. 

It is safe to say that there is scarcely a rubber mix- 
ture that does not contain as an essential ingredient 
some such substance. Of the many processes and sub- 
stances that have increased the efficiency of au- 
tomobile tires, no one of them deserves greater credit 
than the organic accelerator; it has so greatly im- 
proved the quality of rubber mixtures that tires run 
much longer by virtue of it. The autobiographies, 
called curves, strikingly show the gains attained by 
these substances. Without an accelerator, a time of 
two hours is needed to vulcanize a rubber- sulphur 
mixture ; the strength attained is but 1150 pounds per 
square inch; the piece stretches 6% times. Add one 
half of 1 per cent.*of accelerator and a little zinc oxide 
to hustle the accelerator, and the mixture vulcanizes 
in one hour, the finished product showing a strength 
of 2760 pounds and a stretch of 6% times. 

If these tests of mixtures were the only ones used 



THE RUBBER MAN'S COOK-BOOK 55 

in making rubber products, the operation of the tech- 
nical department and of the factory in the industry 
would indeed be simple. The current belief probably 
is that any substance other than rubber and sulphur 
used in tires or rubber shoes is employed to make them 
cheaper. This is far from the case. Hardness and 
resistance to abrasion are properties needed for some 
articles and not for others. If a solid tire for truck 
service were to be created by vulcanizing the composi- 
tion tKat I have just given, it would be soft and flex- 
ible ; it would tear with ease and be of slight value as 
a tire. 

Subject to choice, for the purpose of increasing the 
resistance of finished rubber to abrasion, are a large 
number of substances; but I shall use, as an illustra- 
tion, zinc oxide. This substance is a dry, white powder 
that has for years been used in the manufacture of 
white paints. In one form or another, milady uses it 
for whitening her summer sport shoes. It has some 
use as a mild, non-acid base for ointments. Despite 
the large number of zinc ores throughout the world, 
few possess the high degree of purity required to yield 
good zinc oxide for use in rubber compounds. Pecu- 
liarly, there are but few zinc ore deposits in which lead 
ores are not mixed with the zinc. Freedom from lead 
is an important chemical characteristic of the zinc 
oxide to be used in the rubber trade. So important is 
zinc oxide in rubber mixturefs, so valuable are the prop- 
erties given to rubber compounds by it, that the in- 
dustry in 1919 consumed 71,000 tons of this substance. 

Let us write another formula, in this case consisting 
of zinc oxide one hundred parts by weight, sulphur five 



56 THE REIGN OF RUBBER 

parts, plantation raw rubber one hundred parts, and 
the accelerator hexamethylenetetramine one part. 
The photograph shows the relative volumes of these 
substances after they had been weighed out. The new 
compound cures in about the same length of time, 
forty-five minutes, at a temperature of 290° Fahren- 
heit, as did the other. The autobiography of the test 
specimen though, is quite different. It is harder; 
more force is needed to stretch it. When it extends 
to six times its length, a load of more than 3400 pounds 
to the square inch is required to break it. It resists 
abrasion better. 

The chemist and physicist, who must really be the 
same individual in the rubber testing laboratory, meas- 
ures another property, the energy stored in rubber 
when it is stretched. Engineers compute work in 
terms of resistance to lifting weights- against the force 
of gravity. If one pound of a material of any kind 
be lifted one foot the engineer and physicist call the 
work done the foot-pound. When our rubber test 
piece was stretched in the machine, it was necessary 
for the machine to perform work upon it. From the 
autobiography or stress-strain curve, a definite mean- 
ing regarding an interesting property of rubber is ob- 
tained. This stretched piece has a strong desire to 
return to its original length. That is why it is rubber. 
If you stretch wood and steel, they also have a desire 
to return ; but the distance you can stretch them with- 
out destroying that desire is very small. Rubber, 
however, is something like the small boy who climbs 
the old windmill. He goes up quickly at first; and 
then much slower as he gets near the top. His feet 



THE RUBBER MAN'S COOK-BOOK 57 

lag toward the end ; his enthusiasm seems to die. Rub- 
ber acts in much that way. Yielding easily to a light 
load in the beginning, more and more force must be 
exerted to perform the work of stretching it to its 
maximum distance. 

Engineers say that whenever any substance is lifted 
above the ground against the force of gravity, there 
is stored in it a certain amount of energy some of 
which can be regained in the form of useful work by 
machinery properly designed. Although rubber is not 
stretched against the resistance of gravity, the work 
performed is done against the desire on the part of 
the rubber to return to its original length. From our 
chart we are able to measure the amount of this work 
or energy in the engineer 's unit of foot-pounds and to 
compare the amount of stored energy in the rubber 
with the amount that may be stored in other sub- 
stances. 

Each substance has a definite limit to its ability to 
return to normal condition. Steel, for instance, 
may be stretched but a short distance and still return 
nearly to its original length. If steel be stretched be- 
yond that short distance, which is measured in small 
fractions of inches, it cannot return. This limit of 
stretch beyond which substances cannot return has 
been called, in our books of physics, the elastic limit. 
Thus, if a bar of ordinary steel one inch square and of 
a length sufficient to be placed easily in a testing 
machine have applied upon it a force of 40,000 pounds, 
it can be pulled out only about one-hundredth of an 
inch; from this extension it will return to its original 
length. To break the piece, however, would require 



58 THE EEIGN OF EUBBEB 

68,000 pounds; the same force would stretch it about 
four one-hundredths of an inch. Thus, any load up- 
on this test piece of steel between 40,000 and 68,000 
pounds is too great for it to bear and still return to 
its original dimensions. For almost all metals, the 
elastic limit is decidedly less than the number of 
pounds required to break the piece. 

Rubber is singular and different from other sub- 
stances in the fact that its elastic limit and breaking 
point coincide. One can stretch a piece of rubber to any 
distance under its breaking point; and when the load 
is removed, it promptly returns to approximately its 
original length. This slight increase in the elonga- 
tion after stretch and release, known as the ** perma- 
nent recovery" or '* permanent set" or ''permanent 
elongation," is a characteristic of all rubber articles. 
On long standing, this permanent recovery gradually 
becomes less and less; and it varies widely in rubber 
mixtures of different composition. 

The ability of rubber to store energy is great ; that 
is, we may pull rubber to nearly its breaking point. 
If it were possible to harness this energy so that use- 
ful work could be performed, we should find a rela- 
tively large amount of it stored in rubber. If, in a 
machine, one pound of tempered spring steel be 
stretched just to the elastic limit, an action which 
would require a bar an inch square in section and 
weighing one pound to be loaded with 82,000 pounds, 
one can store in it 95.3 foot-pounds of energy. Hick- 
ory wood when pulled along the grain is elastic enough 
to permit the storing of 122.5 foot-pounds at its elas- 
tic limit. In this way, our pure gum rubber compound, 



THE RUBBER MAN'S COOK-BOOK 59 

without the accelerator that we have already described, 
would permit us to store in it a matter of 3186 foot- 
pounds. However, with the accelerator, we can store 
7633 foot-pounds; the zinc oxide composition, on the 
other hand, would store 7988 foot-pounds. 

But, you protest to the chemist compounder, most 
rubber articles are not white ! Tire treads are black ; 
at least, they are that color when the gray bloom is 
rubbed off. Heels and shoes are usually black. If 
zinc oxide is so valuable a material, why use any other 
dry powder? Then all articles would be white except 
those articles where other colors were desired. But 
you would not be quite happy were the rubbers you 
wear always white, because they would discolor too 
easily ; they are deliberately made black. However, a 
discovery in this field was made which brought into 
use a material that was formerly well known, but that 
entered rubber in a new way. 

Carbon-black is a soot made by incomplete combus- 
tion of natural gas ; it is composed of very fine, light 
particles. Let us now make a new formula in which 
this black dust is used, to see how it compares in physi- 
cal properties with the others. This will lead us to 
the reason for its wide use in the rubber industry. A 
formula composed of rubber one hundred parts by 
weight, zinc oxide three parts, gas-black thirty-five 
parts, sulphur five parts, and the same accelerator 
one part, is a good one. If this composition be vul- 
canized, we find relatively little change in the time 
of vulcanization. When its autobiography is in- 
scribed on the chart, we find that with a cure of 
seventy-five minutes at 290° Fahrenheit, a load of 



60 THE REIGN OF RUBBER 

twelve hundred pounds has stretched the piece only a 
matter of 2.6 times its original length. But a force 
of nearly four thousand pounds to the square inch is 
needed to break it ; and under this load, it has stretched 
to 5.5 times its length. The mixture is therefore stiffer 
and stronger. The piece stores 14,887 foot-pounds. 
In weight it is very much lighter than the zinc oxide 
mixture ; as we find, on measurement, that the specific 
gravity of this particular mixture is only 1.09, a figure 
which means that the weight of a cubic foot is sixty- 
eight pounds; the zinc oxide mixture with a specific 
gravity of 1.56 shows a weight of a cubic foot to be 
ninety-seven pounds. In the formulas approximately 
the same volume of zinc oxide and carbon-black was 
specified. Zinc oxide is heavy and dense, and so a 
cubic foot of the compound weighs more than that 
which contains black. 

The gas-black formula will wear away less readily 
than the others. Since this substance produces radical 
improvement in the physical properties required for 
wearing qualities, it is valuable in the treads of auto- 
mobile tires. The gas-black tread has become stand- 
ard. In the interior of the tire a carbon-black com- 
position would be worthless ; it generates heat as it is 
stretched back and forth. In masses of rubber it be- 
comes a heat insulator, and compositions in which it is 
used become very hot in service. Without organic 
accelerators, though, gas-black compositions are too 
**dead" for practical use; with the accelerator and 
with zinc oxide, they are valuable and economical. 
Zinc oxide alone gives a strong but more resilient com- 
position. 




Courtesy of The B. F. Goodrich Co. 



A SMALL SET OF LABORATORY MILLS AND CALENDERS FOR MIXING AND SHEETING RUBBER 
COMPOUNDS FOR EXPERIMENTAL PURPOSES 




Courtesy of The B. F. Goodrich Co. 



Courtesy of Henry L. Scott & Co. 



A VULCANIZING PRESS, SHOWING THE AUTOMATIC A RUBBER TESTING MACHINE FOR MEAS- 

TEMPERATURE CONTROLLING APPARATUS AND THE URING THE TENSILE STRENGTH, ELONGA- 

RECORDING THERMOMETERS TION, AND THE AUTOBIOGRAPHY OR 

CURVE OF VULCANIZED RUBBER TEST 
PIECES 



THE RUBBER MAN'S COOK-BOOK 61 

Each of these two substances then has its own partic- 
ular properties, and the chemist uses them to improve 
the compositions. We could not do without either 
of them. They are the royal family of the rubber 
pigments. Each rubber chemist chooses which one of 
them is to be the king. One thing is perfectly sure: 
the addition of dry mineral powders is necessary to 
obtain valuable properties in rubber mixtures for dif- 
ferent uses. 

It would not be wise to say that all dry pigments 
used in rubber mixtures should be only zinc oxide and 
gas-black. If that were the case, there would be many 
common articles that would render less service than 
they now do, as each pigment has its own particular 
value and each one is used in rubber for the service 
that it renders. 

We may mention other materials: such as mineral 
rubber, a material derived from pitch and soft, flexible, 
mineral hydrocarbons; rubber "substitutes," resins 
and many others. 

I shall not at this point discuss reclaimed rubber, a 
valuable substance made in the recovery of old vul- 
canized tires, shoes, and so on. Since the saving of 
waste is a most vital part of industry and human man- 
agement, it would be folly for a great industry to per- 
mit the total loss of these waste products. Old iron 
goes back into the melting pot and is reworked into 
various articles. So the rubber industry has suc- 
ceeded in reclaiming its vulcanized products after they 
have performed all the service possible. 

Colored goods introduce another phase of rubber 
compounding. It seems that the human race demands 



62 THE EEIGN OF EUBBEE 

artistic products. To meet this demand, our water- 
bottles are made red by antimony sulphide, or ver- 
milion ; blue products are colored by ultramarine blue, 
greens by chrome greens, and white by proper quan- 
tities of zinc oxide or lithophone. 

So I might decribe probably fifteen hundred differ- 
ent materials that go to make up the twenty to thirty 
thousand articles that are the result of rubber manu- 
facture. A versatile individual must be the rubber 
chemist; for he must understand their sources, com- 
position, and properties. He must know a great deal 
about how each of them affects rubber mixtures. In 
the choice of substances, he combines them to give 
valuable properties. He must make compositions to 
withstand the action of heat, as in the laye-rs which 
separate the plies of cotton in automobile tires ; and, 
too, he must make them to contain air, as in inner 
tubes, to resist abrasion, as in solid tires and pneu- 
matic tire treads, and to be permanent in balloons 
under the action of light and oxidation. Some must 
not swell in oil. He develops special mixtures for 
steam-hose and steam-packing. Throughout the whole 
line, it is special study and expert mixing that produce 
the properties in the rubber necessary for the best serv- 
ice to the consumer. 



CHAPTER V 
RAW RUBBER 

The lips and downs of rubber during its history 
convince us of its elasticity. Until approximately 
four hundred years ago, little was known of it in the 
economy of human life. With relative rapidity it rose 
into an important position; it ascended to heights of 
speculation. Rubber booms came, and rubber bubbles 
burst. It has dropped to the depths of economic de- 
pression, but again rebounded — a varied history and 
an interesting one. 

Columbus seems to be the European who first saw in 
the Americas a peculiar elastic substance. On re- 
turning to Europe after his second voyage, he told 
about it. Subsequent travelers made records of the 
substance. 

Antonio de Herrera Tordesillas, one of the most 
prominent historians of Spain, writing in 1615 ''The 
Greneral History of the Voyages of the Castilians in 
the Islands of America, ' ' evidently loved a ball-game, 
for he says: 

The ball was made of the gum of a tree that grows in hot 
countries, which having holes made in it distils great white 
drops that soon harden, and being worked and moulded 
together turn as black as pitch. The balls made thereof, 
though hard and heavy to the hand, did bound and fly as our 

63 



64 THE REIGN OF RUBBER 

foot-balls, there being no need to blow them. . . . They 
might strike it every time it rebounded, which it would do 
several times one after another, in so much that it looked as 
if it had been alive. 

He alludes to the natives of Tierra Firme, who ''on 
their festivals, painted or daub'd themselves with a 
sort of clammy gum, sticking on it feathers of several 
colors. ' ' 

F. Juan de Torquemada, in the third volume of his 
*'De La Monarquia Indiana," of which the first edi- 
tion appeared in 1615, describes the Mexican Indians 
as making shoes, head-gear, clothing, and other water- 
tight articles of the gum of a tree. 

The actual introduction of any useful articles into 
Europe seems to have followed the colonization of 
Brazil in the early part of the sixteenth century by 
the Portuguese. 

In 1736, in company with Bouguer and Godin, La 
Condamine, a French savant, was sent by the king 
of France to South America for the purpose of meas- 
uring a degree of the meridian. On their return jour- 
ney to Europe, these men brought the first specimen 
of caoutchouc from Peru, by way of the Amazon River. 
La Condamine reported having also found this * ' most 
singular resin" to the north of Quito in Ecuador, exud- 
ing from a tree named heve or hyeve. It was called 
pao de xyringa by the Portuguese colonists. The re- 
sult of his observations was published in the ''Trans- 
actions de V Academic des Sciences," wherein he de- 
scribed the various methods of collecting the juice and 







Courtesy of The B. F. Goodrich Co. 

A RUBBER PLANTATION IN SUMATRA 




Courtesy of The Commercial Museum 
of the Colonial Institution — Amsterdam, 
Holland 

COAGULATION TUBS IN THE "GO-DOWN" 
OF THE PLANTATION 




Courtesy of The Commercial Museum 
of the Colonial Institution — Amsterdam, 
Holland 

WASHING COAGULATED BUT NOT DRIED RAW 

RUBBER IN THE WASHING ROOM OF THE 

PLANTATION 



EAW RUBBER 65 

of treating it for the production of many useful ar- 
ticles. 

Herissant and Macquer published in 1761, in the 
''Memoires de 1 'Academic, " the results of the first 
chemical investigations of India rubber solutions. 
Five years later, Macquer reported fully on the means 
of dissolving the ''resin caoutchouc" in ether, and 
on repeatedly coating forms, so that they retained a 
covering of the gum after the evaporation of the ether. 

In 1759 the government of Para presented to the 
king of Portugal a suit of rubber clothes; four years 
previously he had sent several pairs of his boots to 
Brazil to be waterproofed. One of the Portuguese 
drank some of the milk, but his stomach did not care 
to be waterproofed and he passed on to his fathers. 

An Italian engineer suggested in 1791 the suitability 
of petroleum as a solvent; but he was ahead of his 
time, for that substance did not come into general use 
until as late as 1860, with the exploitation of the 
American oil-fields. 

But on May 2, 1791, Samuel Peal was granted in 
England the first known caoutchouc patent. It was 
for a method of rendering ''perfectly waterproof all 
kinds of leather, cotton, linen, and woolen cloths, etc. ' ' 
His coating consisted of India rubber dissolved "by 
distillation or by infusion in a small quantity of tur- 
pentine over a brisk fire, or by infusion in other spirits 
and in most kinds of oil ; or of Indian rubber used in 
its native fluid state." 

Samples of this crude rubber coming into England 
found their way into various laboratories, where 



66 THE EEIGN OF RUBBER 

the great chemist Priestley examined them in 1770. 

What is this raw rubber? If you were so to travel 
around the world as to allow yourself journeys into 
tropical countries, at almost any point 250 miles on 
either side of the equator you would find growing wild 
in the jungles certain evergreen trees, vines, and even 
shrubs which, when the bark is broken, give forth a 
white milk. This milk, which we might naturally call 
sap, or technically latex, if allowed to stand in the air 
and evaporate, leaves a brown residue. The residue 
is raw rubber. The milk comes from glands in the 
inner layers of the bark. From more than five hun- 
dred individual species in this great group of milk- 
producing trees can be obtained, after evaporation or 
other treatment, the brown, elastic substance. 

The trees giving the best quality of raw rubber are 
those mentioned by La Condamine ; the botanist named 
the species Hevea hrasiliensib-, a modification of the 
original. Naturally, after the discovery of the trees in 
South America and the knowledge of the wonderful 
properties of the rubber left after evaporation on shoes 
and fabrics, the South Americans pushed forward the 
making of rubber for export to Europe, where com- 
mercial development of the product was progressing. 
So in 1825 Brazil exported thirty tons of this dark 
brown material from the rubber-trees. In 1850 the 
exportation had jumped to 1467 tons, and in 1897 to 
21,260 tons. 

In the jungle these wild trees of the Hevea brasili- 
ensis species grow to a height of seventy-six to one 
hundred feet and measure from four and one half to 
twelve feet in circumference. The restriction of the 



RAW RUBBER 67 

branches, which are small, largely to the crown of the 
tree gives, as do the pine-trees from which turpentine 
is obtained in our Southland, a large area of bark for 
tapping. Where the temperature averages about sev- 
enty degrees Fahrenheit and the annual rainfall is at 
least ninety inches, the trees flourish. The natural 
transportation lines in these aboriginal countries are 
along the rivers ; consequently, the areas exploited in 
collecting rubber in South America have been along 
the Amazon River and its tributaries. 

Here, the native rubber tapper leads anything but 
an easy life. The jungles are dense, overrun by in- 
numerable vines and creepers, and filled with snakes, 
tarantulas, and poisonous ants. Since the flood sea- 
son occurs from November to May, during which time 
the rivers overflow their banks, the rubber tapper is 
obliged to spend his time in his hut, which is built on 
piles above the water. During the rest of the year or 
the dry season, vegetation is luxuriant. Innumerable 
swamps from which fevers and disease come, though, 
add to the discomforts of this poor native. 
I He rises about four in the morning, while it is still 
dark, and starts out into the forest, with a small 
Ihatchet and a tin bucket. On the first of two trips 
laround his territory, with the hatchet, he gashes long 
Wounds into the rubber-trees. The resulting flow of 
3ap or latex runs down the tree and into a little tin 
(jup below the gash. In order to make his living, it 
: s necessary for the rubber tapper to cover a large ter- 
ritory by winding paths. Breaking his way through 
;he rapidly growing vegetation in the jungle, he taps 
md collects latex from seventy to one hundred trees in 



68 THE EEIGN OF EUBBER 

[the course of a day. After he has properly tapped 
1 the trees in his territory, he goes back over it and 
J pours the milk from the little cups into his tin bucket. 
I His milk collected, he comes back to his hut which, 
■ during the dry season, is usually a temporary one on 
the ground. While he prepares his -meal, he lights a 
fire made from wood and specially collected palm 
I nuts. Over this fire he places a conical, baked clay 
I flue to concentrate the smoke. Obtaining a dense, 
hot smoke, he begins the work of preparing the raw 
I rubber for market. He warms a long stick or a paddle 
over the fire ; then he pours some milk upon it. This 
j he rotates in the smoke until the milk has dried on the 
i stick. Again he pours the milk, and again he dries 
it over the fire. If he is not asphyxiated at the out- 
set of the performance, he keeps at it, building up 
layer after layer of evaporated rubber until a mass 
is obtained nine or ten inches in diameter and about 
eighteen inches to two feet in length. This forms 
the biscuit of wild rubber called ''fine para" seen in 
our markets. Weighing about sixty to eighty 
pounds, it constitutes a day's work for the tapper. 
It smells like fine old Virginia ham. 

At the end of the day, which for him is about three 
in the afternoon, he may be found in his hammock, 
with sore eyes, parched and smoked face, bitten by 
insects, and covered with soot. It is no wonder that 
we find a high death-rate in the Brazilian swamps 
and that there has been from the beginning a steady 
deterioration in both numbers and quality of labor. 
At the end of the dry season, for the tapper cannot 
work at all during the wet or rainy season, he collects 




Copyright Keystone View Company 

FIELD HANDS GATHERING COTTON, WHICH IS THE BACKBONE OF RUBBER ARTICLES 



EAW RUBBER 69 

and binds together the product of a year's work, and 
floats it down the river to the nearest chief, who ac- 
cepts it in payment for money previously advanced. 

The Brazilian rubber industry was important for -a 
considerable number of years, but the history of it is 
dark and morbid. The prevailing practice has been 
to make peons, mere slaves, out of these poor Indians. 
Couple this with the heavy government taxes and fees, 
the high freight-rates, the dishonest gradings of rub- 
ber, and you will not wonder that the collection of 
raw rubber in Brazil has sagged during recent years. 
Attempts have been made to import farmers ; but be- 
cause of unhealthy conditions, the lack of proper food, 
the absence of business ability on the part of the 'Bra- 
zilians, their indifference to progress, and the damp 
air and lands, the attempts came to naught. 

The slowness of evaporating the several coats of 
latex to produce the thin layers of rubber built up step 
by step into the biscuit, together possibly with the 
chemical constituents of the smoke, served to yield a 
tough, high-quality raw rubber. Although the native 
lost his health and life, he succeeded in producing the 
finest grade of crude rubber that came into the mar- 
ket. This was known as ''fine hard para." It is 
singular how a name is preserved, for Para was the 
original port of shipment. In later years the port 
became Manaos, although the name ''para" rubber was 
still given to the best grade from Brazil. Not only 
that, but all high-grade rubber is colloquially known as 
"para" rubber. If the workman is not skilled, the 
layers on his biscuit are apt to be thick and soft ; the 
grade "medium" is the result. When the tapper 



70 THE EEIGN OF RUBBER 

collects the little strips of rubber that have gath- 
ered on the trees, and on the leaves on the ground, 
he rolls them, full of dirt and bark, into balls known 
as "coarse" or *'sernamby." In the bottom of the 
cups are always little cakes of rubber; these come 
in mass form into the market under the name 
''cameta." These are but a few of the many grades, 
each distinct from the other, produced from this exuda- 
tion from the wild trees in the Amazon Valley. There- 
fore the rubber manufacturers' problem during the 
days when wild rubber was at its ascendancy, was one 
of making the correct selection for many different pro- 
ducts. Because all the grades were wet, it was neces- 
sary, and still is, to wash these wild crude rubbers 
free from sand and other particles of foreign matter 
and to dry them before they are ready for use in the 
factories. In washing and drying there is a loss of 
weight called "shrinkage," from both dirt and mois- 
ture. In the highest grade the shrinkage is about 17 
per cent.; in the softer, weaker grade, such as the 
cameta, it runs as high as 48 per cent. 

Rubber-trees in different districts seem to be a little 
unlike even in the same species. This, with slightly 
differing methods of production, results in many 
grades. Names of different rivers are used in desig- 
nating grades — ^Acre, Tapajos, Madeira, and so on. 
Since the best trees and the best rubbers from 
them come from the upper reaches of the Amazon 
River, it has been natural for the trade to call these 
products "up-river." So "up-river fine para" is the 
highest grade known, except "beni," which is the 
best of the up-river grades. 



RAW RUBBER 71 

Men somehow are never satisfied. No sooner was 
wild rubber known than suggestions came to plant the 
trees. Dr. James Howison, an English surgeon at 
Pullopinang, in 1789 discovered a vine giving a milk 
that possessed the properties of the South American 
caoutchouc. He wrote about it in 1800: *' Should it_ 
ever be deemed an object to attempt plantations of the 
elastic-gum vine in Bengal, I would recommend the 
foot of the Chittagong, Rajmahal, and Bauglipore 
Hills,' as situations where there is every probability 
of succeeding, being very similar in soil and climate 
to the places of its growth on Prince of "Wales * Island. ' ' 
Howison thus originated the plantation idea. 

Later Thomas Hancock, in 1834, expressed in the 
* * Grardener 's Chronical" the probability of cultivating 
the best kind of caoutchouc-bearing plant of the East 
and West Indies. The supply at that time — two to 
three tons weekly — did not seem great enough! It 
came to England in poor condition, wet, sticky, and 
dirty. 

Fortunately, in the early sixties one man saw a vis- 
ion of the future and carried it out. Henry A. Wick- 
ham of London had spent several years in the Brazil- 
ian forests. A man of keen mind, intrepid force of 
character, and vision, he studied the rubber-trees and 
went so far as to plant trees on the Tapajos Plateau in 
Brazil. He posted himself thoroughly on the botany, 
the method of growth, soils, water supplies, and every 
other possible question connected with the Hevea tree. 
He proposed to London that seeds from the Hevea 
brasiliensis tree be gathered and planted for the pro- 
duction of cultivated rubber-trees. Others had tried 



72 THE REIGN OF RUBBER 

it but failed ; they had chosen the wrong species. Mark- 
ham had sent Collins to investigate. Cross had 
brought back Castilloa seedlings ; but the plants never 
thrived, and the rubber gained was of low grade. Sir 
Joseph Hooker, then director of Kew Botanic Gardens, 
believed in Wickham's plan and interested Sir Clem- 
ents Markham of the India Ofi&ce. Luckily, Wick- 
ham was given the responsibility of making the exper- 
iment, and by rare good fortune he was left unham- 
pered by instructions. We must commend the English 
for one thing; when once their minds are made up, 
they see a thing through. 

Setting out again then for Brazil, Wickham went 
immediately to the territory on the Tapajos Plateau, 
well up the Amazon River, where he had been con- 
sidering a plantation enter.prise. He writes a roman- 
tic story of his experiences. Singularly, discouraging 
circumstances were turned into success by an accident. 
While he was in the district, word came to him 
of the arrival of the steamship Amasonas, Captain 
Murray at the helm, which was the first of the new 
''Inman line of Steamships — Liverpool to the Alto- 
Amazon direct." A few days later the information 
arrived that this fine steamship, through a mix-up, had 
been abandoned by the supercargoes and left on the 
captain's hands, with nothing to take back for the 
return voyage to Liverpool. 

Wickham was nothing if not an opportunist. He 
had neither cash nor credit. The seed was just ripen- 
ing on the trees. But he boldly wrote to Captain 
Murray, chartered the ship on behalf of the Govern- 
ment of India, and made an appointment to meet him 



EAW RUBBER 73 

at the junction of the Tapajos and Amazon rivers. 
Here he was in the jungle, with an impatient captain 
waiting at port on an empty steamship. Jumping into 
an Indian canoe, he paddled up the Tapajos, a danger- 
ous trip, particularly in that season, and struck back 
into the woods where he knew the full-grown Hevea 
trees to be. Out of seventeen varieties, he chose seeds 
from the black or best grade of the tree. Accompanied 
by Indians he daily went through the forests and 
packeS pannier baskets with loads of seed. It was a 
delicate operation, for the seed is rich in a heavy oil 
that quickly becomes rancid, a condition that destroys 
the power of germination. With remarkable astute- 
ness he did what no other 'had done — packed the seed 
to avoid decay. Once on board the steamer he went to 
the city of Para, from which port cleaTance papers were 
necessary before he could go to sea with his cargo. 

Wickham says in his narrative: **It was perfectly 
certain in my mind that if the authorities guessed the 
purpose of what I had on board, we should be detained 
under the plea of instructions from the Central Gov- 
ernment at Rio, if not interdicted altogether." Any 
such delay would have rendered his seeds useless. He 
had, however, a friend in the person of Consul Green, 
who entered into the spirit of the occasion and made 
a special call with him upon the chief of that district. 
They represented that they had ''exceedingly delicate 
botanical specimens specially designed for delivery to 
Her Britannic Majesty's own Royal Gardens at Kew." 
This seems to have been impressive; and, after the 
usual complimentary interview in the best Portuguese 
manner, they were permitted to clear port. 



74 THE REIGN OF RUBBER 

On the voyage Wickham took exceeding care of his 
precious seeds. During June, 1876, he arrived in 
England. A special train was sent down to meet him 
at Liverpool, and the seven thousand young seeds 
were promptly planted in the Botanical Gardens at 
Kew. A fortnight later they had .sprouted. Then an 
equally great problem confronted the experimenters, 
for no plans had been made to send the shoots to any 
of the English colonies. They were originally intended 
for southern Borneo; but because of the depres- 
sion in business at the time, the government forestry 
appropriation had been decreased. Governments cut 
down the amount for research in those days as now. 
As a result of this decrease, the seeds were sent to 
the Eastern Tropic Botanical Gardens in Ceylon. 
Thus the plantation industry was started. Wickham 
was knighted in recognition of these services. 

In 1877 twenty-two trees started in Ceylon were sent 
to Singapore in the Straits Settlements south of the 
Malay Peninsula. Some were planted in Singapore 
gardens and the rest taken to Perak. A few of these 
original trees are still standing. One of them is said 
to be the biggest plantation tree in girth yet recorded. 

They bore fruit in Singapore first in 1881, and 
seed was sent to Borneo and Malaya. Because they 
had been making good profits from the growing of tea, 
the planters in Ceylon did not take hold of rubber 
planting with the same aggressiveness as did the plant- 
ers of Malaya. But in Malaya, backed by financial in- 
terests in Europe and tired of the struggle to make a 
living out of coffee, rubber appealed to them, and they 
planted trees wherever possible. The first trees of 



EAW EUBBER 75 

the Ceylon plantation bloomed in 1881 at Heneratgoda, 
sixteen miles from Colombo. That year the first ex- 
periment in tapping began. Problems of how to tap 
and when to tap, of how many trees to plant to the 
acre, of the diseases of trees and methods of treatment, 
and of the proper handling of latex, have filled volumes 
of literature. It is, in a marked degree, due to the 
enterprise of the English and Dutch scientists and 
business men that the plantation industry has suc- 
ceeded and has become so tremendously important in 
the world 's markets. 

From the wilds of Brazil to the cleanliness and uni- 
formity of the plantations of the East necessitates a 
change of picture. Here the trees are laid out in or- 
chards as even, regular, and well cultivated as apple 
orchards. There are little Chinese and native rubber 
farms and big ones, owned by corporations with head- 
quarters in London, Amsterdam, and America. On the 
plantations the health of the workers is taken care of. 
Because there is not labor enough in these districts, it 
has become necessary to bring in coolies from China 
and India. In order to make the conditions as com- 
fortable for them as their natural state of living re- 
quires, the health, the food, and the life of these people 
are watched, and the result has been economy in op- 
eration and increase in production. 

To start a plantation, the jungle must be cleared in 
a location where drainage and soil are right. It is a 
long, expensive task to prepare land for the reception 
of the rubber-tree sprouts, which are set out in rows, 
usually about one hundred to two hundred to an acre. 
Then begins the important problem of exterminating 



76 THE REIGN OF EUBBEE 

weeds, which in these moist, tropical regions grow at 
a discouraging rate. 

The tapping of a rubber-tree is an art that requires 
a delicate touch and a sure hand. By tapping is 
meant the cutting of the tree so that the latex will 
flow freely in a clean, uncontaminated condition, into 
a properly placed cup. Scientists spend their time 
in improving the yields by processes of tapping at 
proper intervals, by care of the trees, by selecting 
seeds for future plantations from those that give the 
greatest yield of rubber. Rubber-trees are being 
scientifically bred and trained, like cows, to give 
greater quantities of milk. A diagonal cut extending 
one third or one quarter of the way around the tree is 
one of the best of many methods. This is made with 
a razor-sharp knife of special construction, whose blade 
is so thin that twenty tappings may be made side by 
side in one inch of bark. If the cut be not sufficiently 
deep, the full quantity of latex is not obtained ; if the 
cut be too deep, the tree is injured. Tapping is there- 
fore so important that only a skilled laborer is per- 
mitted to do it. Because the latex is found in milk 
ducts, it is necessary to tap a tree daily. These glands 
seem to rebuild themselves after a few days' rest. By 
noon, when he has tapped 450 trees, the tapper's work 
is finished ; at eight or eight-thirty in the morning, the 
work of collecting the latex from the little cups begins. 
Usually on the large plantations metal milk cans are 
used ; and when the collector has filled his cans, he takes 
them to a collecting shed where his latex is weighed. 

The plantations are milk factories. Here, cleanli- 
ness is as necessary as in a dairy. Rubber milk is 












Courtesy of The B. F. Goodrich Co. 

SEVERAL GRADES OF PLANTATION-GROWN AND WILD RUBBER 
CAUCHO BALL AMBER BLANKET CREPE 

PLANTATION TREE SCRAP 
SMOKED SHEETS ROLL BROWN CREPE 

PALE CREPE UP-RIVER COARSE PARA 

CONGO UP-RIVER FINE PARA 



EAW EUBBER 77 

even something like cow's milk. Both contain finely 
divided particles suspended in water; but in one case 
it is 3 to 5 per cent, of fat and in the other 25 to 35 
per cent, of rubber. The farmer centrifuges milk 
and gets cream, but milk separators do not work on 
Eevea latex. Since the rubber will not rise as a 
cream, the planters add acetic acid to it to congeal or 
coagulate it. 

On large plantations, the first operation is to strain 
the latex carefully in order to free it from dirt and 
from the curds or flocks that have been formed during 
transportation. Into appointed vats of correct size 
the latex is then poured, and with it is intimately 
mixed a dilute solution of acetic acid. This causes 
immediate coagulation into a mass of soft, white dough. 
The acid must be added within twenty-four hours, or 
spontaneous coagulation will set in, caused probably 
by the rapid action of bacteria that seem to sour the 
rubber milk just as bacteria sour cow's milk. After 
this soft, white dough has formed, it is put into a ma- 
chine which tears it up into small pieces and presses out 
the excess of water and chemicals. It then goes 
through a washing machine, where it is washed with 
clean, filtered water; during this process it gradually 
hardens by the simple matting together of the rubber 
particles that had previously existed in the latex. On 
the larger plantations, it is usually coagulated in bulk, 
either in a big tank or in glazed earthenware jars of 
200 to 250 quarts capacity. 

In order to produce the light yellow crepe rubber, 
there is mixed with the acetic acid a small quan- 
tity of what the chemist knows as sodium bisul- 



78 THE EEIGN OF EUBBER 

phite. The rubber comes from the rolls of the washer 
in a rough irregular sheet. This wet rubber is hung 
in dry rooms, like clothes on a line. Before it is dry, 
the rubber is white from the presence of water. From 
the dry room, the sodium bisulphite having bleached 
it, it emerges pale yellow in color. We call it **pale 
crepe." 

The Amazon fine para smells smoky, like ham. .So 
older rubber men thought smoked rubber to be the best. 
The planters met the demand for the smoked prod- 
uct with the grade known as ''smoked sheets." To 
make this, the method of coagulation is essentially 
the same, but without the sodium bisulphite. The co- 
agulum is then rolled between washing rolls. When 
clean, it is passed between rollers that have been cut 
in such a way as to produce a pattern known usually 
as *'ribs" upon the soft, wet mass. Less time is re- 
quired in washing and handling smoked sheets than 
in producing crepe, but there is danger that all the 
impurities and serum are not removed. 

The Eubber Growers' Association of Great Britain, 
and similar associations among the Dutch, have worked 
out methods to produce ''even size, even weight, even 
thickness" of sheets. After the rolled sheets with the 
pattern or ribs come from the mills, they are hung up 
to dry. Then they are smoked in a smoke-house, 
much as we smoke hams. Great care is taken that 
the smoking be uniform, that it be not too hot, and 
that the color be regular; for by irregularity of han- 
dling the smoked sheets comes a large variety of de- 
fects that grade down quality. There are ten or a 
dozen different types of smoked sheets produced by 



RAW RUBBER 79 

different conditions of coagulating and smoking. 
There are bubbly sheets, moldy sheets, tacky sheets, 
dark colors, and light colors. To the farmer, milk is 
milk and cream is cream; he disposes of it all in one 
grade. The problem is not so simple for the rubber 
planter. Besides pale crepe and smoked sheets, there 
are clots in the strainers, bark scrap, and cup film, 
which are often worked together and called *'compo." 

The natives, too, on their little farms grow rubber- 
trees. ' They, however, follow the simple plan of pour- 
ing latex into pans, permitting it to evaporate until 
it has coagulated. Then they roll it up with a sort 
of rolling pin to squeeze the extra water out, and 
hang it on the fence to dry. This process yields a 
softer product, one that is wet, somewhat oxidized, 
and not of a high quality. The enterprising China- 
men trade rice and clothing for the rubber produced 
by these natives, and take it to central stations, where 
it is washed and dried. We call it ''amber sheets," 
which are rated according to color. 

One might think the rubber planter to have finished 
when he takes his sheet from the dry room. This is 
far from the case; for then a number of different 
forces begin to act upon it. Because sunlight causes 
rapid oxidation, the rubber must be kept from it ; be- 
cause heat causes a chemical change that renders 
rubber less useful, it must be kept as cool as possible. 
Care must be taken in packing and storage. Bacteria 
affect the rubber. Oil from machines produces soft 
spots. If it is packed in the rain or if it is not properly 
dried, mold develops on it; and some mold is delete- 
rious. The proper kind of boxes in which to pack the 



80 THE REIGN OF RUBBER 

rubber has been the subject of much study; for if the 
box, which holds about two hundred pounds and is 
approximately cubical in shape, be weak and break, 
the rubber may be contaminated with chips. Chips 
in inner tubes of automobile tires might affect one's 
good humor. 

A glance at the map will show you the areas from 
which plantation rubber chiefly comes. The vicinity 
of the Malay Straits seems to offer that peculiar 
combination of soil, climate, and labor around which 
the successful development of the plantations has 
grown. From the little experimental trees set out in 
Ceylon, there was not a great or rapid development 
until the automobile brought a demand for rubber 
tires. This demand induced further planting. Statis- 
tics show that in 1900 there were four long tons of 
plantation rubber recorded, with 26,750 tons of wild 
rubber from Brazil and 27,136 tons from the rest of 
the world, or a total of 53,890 tons. For the first 
time in the history of rubber it had a statistical posi- 
tion that marked it as permanent and large enough 
a product to warrant the attention of the world. The 
industry then rapidly grew, so that in 1907 one thou- 
sand tons of plantation rubber are recorded, with 
38,000 of wild rubber from Brazil and 30,000 tons from 
the rest of the world. In the same year, there were a 
total of 506,550 acres of ground under rubber cultiva- 
tion. The automobile in those years became a potent 
factor, and the demand for tires rapidly increased. 
Consequently predictions of the optimists became 
realized: in 1909, plantation rubber had jumped to 
3600 tons and wild rubber to a total of about 66,000 



EAW RUBBER 81 

tons. The area under cultivation had grown to 
861,000 acres. 

Then occurred the famous and spectacular '* rubber 
boom" that has gone down into history like the many 
speculative entanglements. Never has there been a 
more memorable year in the history of rubber than 
that of 1910. Men went as wild in England during this 
period of over-speculation as they did at the time of 
the South Sea Bubble or of the tulip mania in Holland. 
Our statistics show that crude rubber prices varied 
from a low point of about forty cents in the year 1878 
to a high one of $3.12 a pound in New York in April, 
1910. During those exciting days in London, investors 
even paid as much as 4600 per cent, premium for 
shares in rubber plantations. Speculators who knew 
little of rubber besieged bank doors when the list of a 
new company was opened. Waitresses, hair-dressers, 
elevator-boys speculated and made, at least on paper, 
money enough to retire to the ranks of the "bloated 
bondholders.'^ Then came the break, and rubber 
prices have steadily declined ever since. 

The stimulus to planting, however, was permanent, 
the total area under cultivation rapidly increasing, 
until in 1915 it had reached 2,293,000 acres, and in 
the next five years, 3,020,750 acres. The production 
of plantation rubber likewise kept increasing, as did 
the production of Brazilian and other wild rubber, 
but less rapidly. As a result, in 1915 there were 
107,860 tons of plantation rubber, 37,220 tons of 
Brazilian, and the rest of the world yielded only 
13,616 tons. In 1920 the plantations put into the 
market 304,816 tons, Brazil had fallen to 30,790, and 



82 THE REIGN OF RUBBER 

the remainder of the world, to 8125 tons. Seventy-five 
per cent, of all this rubber came to America, and about 
70 per cent, went into tires manufactured here and else- 
where. The far-sighted planter had won. 

During the boom of 1919 and the depression of 1920 
we again notice rubber's elasticity. For while mil- 
lions were made in the boom of 1910, millions were 
lost in the depression of 1920. In this depression, 
over-production played the star part. After the 
World War the demand for automobile tires and rub- 
ber products rapidly increased; the supply of crude 
rubber increased in about the same ratio. But with 
the depression, the planters were in a difficult situa- 
tion. The larger number of estates were owned by 
the English, who consequently felt the slump most 
keenly. Singapore, instead of Para or Manaos, had 
become the world's shipping center, with London the 
world's rubber financial center. The end of Decem- 
ber, 1921, showed a total acreage under cultivation in 
British Malaya of 1,760,000 acres ; in the Dutch East 
Indies of 875,000 acres; in Ceylon of 410,000 acres; 
and in the other countries of 276,000 acres, making a 
total of 3,321,000 acres. The total amount in bearing 
and still solvent amounted to approximately 2,200,000 
acres. These estates gave an average yield of 316 
pounds to the acre, so that the production in 1920 was 
309,100 tons. The demand for use could not possibly 
be more than 180,000 tons. With a visible supply of 
well over 300,000 tons, there was little hope for a pro- 
fitable market. Since a selling price of eightpence per 
pound was under the cost of production, strenuous ef- 



EAW EUBBER 83 

forts were required to maintain the solvency of the 
rubber plantation companies. 

The real needs of the plantation industry may be 
summed up thus: Prices must be sufficiently low to 
maintain the economic balance of supply and demand ; 
cheaper production must come from efiBcient and eco- 
nomical management. These needs met, if world- 
business conditions be sound and normal, the planta- 
tion industry will keep alive, growing, and successful. 
From the rapidity with which unattended estates in the 
tropics become overrun by weeds, there is, though, a 
serious condition confronting the plantation industry 
and the world's use of rubber. The maintenance 
of a rubber plantation in good bearing condition re- 
quires labor to be expended in removing weeds and 
treating tree disease, regardless of any tapping or 
profitable output. When there is no money to be real- 
ized, or so little that what is realized is less than the 
cost of production, it is natural to let young orchards 
lie unattended. The result is an outgrowth of weeds 
which rapidly chokes the young trees. The care and 
money that have been spent in clearing the jungle are 
thus lost, and years will be required to bring many 
thousands of these acres back into good condition. 

It is still too early to prophesy the extent of the 
labor problem in the Malay Straits. Every estate is 
cutting down its labor. Coolies are returning to India 
or China. Emigration has become greater than im- 
migration. When production is required, it will take 
a long time and an expensive process to recruit these 
coolies again and train them for the work. On large 



84 THE REIGN OF EUBBER 

estates and on small ones the cost of production, how- 
ever, must be brought down low enough to permit 
profits to be made at prevailing prices. 

I have thus far spoken but little of the wild rubber 
produced outside South America ; and but little need be 
said, in view of its declining quantity. Rubber has 
been produced in Africa. The qualities were as vari- 
able as the climate and the peoples of that great coun- 
try. The majority of processes for obtaining rubber 
from the latex were crude in the extreme. Much of it 
was obtained by spontaneous coagulation on standing, 
some by heating of the latex, and some by the use of 
juices from trees and vines. Foul smelling, it all 
needed washing; and the rubber man soon learned 
to recognize the grade of rubber by the odor. 

Experiments have been tried in the Philippine 
Islands, where it has been found that the Ceard tree 
will grow rapidly and come into bearing under cultiva- 
tion in from three to ten years. Crop conditions are 
favorable in the southern part of the Philippines out- 
side of the typhoon belt, but no forward strides have 
been made. Development probably is retarded by the 
laws prohibiting a corporation from engaging in cul- 
tivation or control of more than twenty-five hundred 
acres of land. The Far East has the start, therefore, 
in plantation rubber production, and it is doubtful 
if any other country will for many years catch up with 
it. 

There is one country, though, in which rubber has 
had a spectacular rise and fall; namely, Mexico. In 
1852 Dr. J. M. Bigelow discovered a plant in the form 
of a small shrub that contained rubber in the wood. It 



EAW EUBBEE 85 

was called guayule by the Mexican peon. No utili- 
zation of it, however, except by natives had been made 
until 1888, when a company went to Mexico and ob- 
tained a large quantity of the shrub, from which to ex- 
tract the rubber. Later, the methods of extraction 
were developed to the point where the industry became 
a large commercial enterprise with many millions of 
dollars invested in it. Large supplies of the shrub 
were used, many thousand tons of the product being 
employed in the rubber industry. But the rise in vol- 
ume of the plantation grades, the decrease in the cost 
of those grades, and the political conditions in Mexico 
have led to a gradual decrease of guayule in the mar- 
kets. 

Booms in the industry have led also to a study of 
every possible plant from which rubber might be ob- 
tained. In late years surveys have been made of 
western North American shrubs; even the Carnegie 
Institution and the University of California have pub- 
lished documents giving the rubber content of some 
species. The work was originally undertaken as a 
war measure for emergency supplies. Energetic 
Americans studied about 225 species of western North 
American plants, which they grouped into two classes : 
one in which rubber occurs in solid particles, as in the 
Chrysothamnus ; the other in which it occurs in sap, 
as in the milkweed and Indian hemp. They seem con- 
vinced that if natural rubber is ever produced in the 
United States in commercial quantities, it will come 
from plants the maceration of which will result in the 
isolation of small quantites of rubber from much ex- 
traneous material. The cultivation will require large 



86 THE REIGN OF RUBBER 

areas, and therefore cheap land. But the belief is that 
these plants can be profitably handled only by machin- 
ery, and that they will yield, in addition to the rubber 
obtained, paper pulp or by-products of value. The 
investigators seem to think that the desert milkweed 
promises most. However, the quantity of rubber 
seems to vary largely, ranging from about 1 per cent, 
up to 8 per cent, in the stem and leaves. This project, 
I think, may be left as something for future consid- 
eration, but not of particular moment to us at the pres- 
ent time. 

Much has been written about synthetic rubber, and 
there was a time when the chemists of the world 
seemed to feel that Old Mother Nature could be pushed 
out of commission so far as rubber was concerned. Be- 
cause every rubber chemist has been taught how the 
Germans succeeded in making indigo from coal-tar, 
every chemist has been led to believe that if he be but 
diligent enough he will find it possible to make any sub- 
stance known in nature by the method of synthetic or- 
ganic chemistry. The ''race for rubber" was a merry 
one while it lasted, but Nature won. To be sure, she 
was aided by intrepid Englishmen and Dutchmen, so 
that it is probably safer to say that in the race between 
chemistry and the planters, the planters won. Grades 
of synthetic rubber were produced in some quantity in 
Germany during the war. Although this material 
could be vulcanized, artificial rubber, by whatever 
means made, has, up to the present time, never been 
produced in quality of a finished product equal to 
that of Mother Nature's first attempt. 

There are some cousins of rubber. Three of these 



EAW EUBBEK 87 

are of marked importance: gutta-percha, balata, and 
chicle. Gutta-percha has high electrical resistance, 
and is easy to handle in factory production. This 
has given it great importance in the manufacture of 
submarine cables, in which it is used as an insulating 
material of permanent nature. 

The chief use of balata is somewhat the same as 
that of gutta-percha; although in the form of the ad- 
hesive layers between plies of fabric in belting, it has 
come lo have a considerable commercial value. Used 
in the covers of golf-balls, gutta-percha and balata 
have found much use of a daily and intimate character. 

Chewing-gum is of interest to us, since the base that 
gives it its resilient properties when masticated, is 
chicle. Chicle is a resilient gum derived from a milky 
latex. The bulk of the world's supply comes from 
Mexico and British Honduras, although there is an- 
other variety exploited in Colombia that is softer and 
less valuable. 

Chicle seems to play a pretty large part in our lives 
when one considers that 9,859,000 pounds were im- 
ported in the year 1920. Virtually the total amount 
of these importations is utilized by the American chew- 
ing-gum industry, the value or manufactured output of 
which in 1920 represented a retail business of $100,- 
000,000. 



CHAPTER VI 
EECLAIMINO WASTE 

America is supposed to be a wasteful nation. The 
lumberman has from the beginning of our occupation 
of this country followed pretty generally the practice 
of skimming the cream. Out of the millions of cubic 
feet of wood in the forests an appallingly small per- 
centage of it is finally worked up into useful products. 
Contrariwise, almost all of the old iron is collected 
and remelted ; the steel industry utilizes its waste prod- 
ucts. 

There is a difference between the old or scrap prod- 
ucts and the by-products from industry. Many in- 
dustries produce substances other than the chief ones, 
which are sold to advantage. The dye industry is built 
upon coal-tar, a by-product in the manufacture of coke. 
Coke is necessary to steel manufacture, but steel has 
no use for tar. 

The rubber industry has few by-products. It does, 
though, have its scrap products, The treads of tires 
wear down, the soles of shoes become thin, but both 
articles still contain a large proportion of vulcanized 
rubber. By getting rid of the sulphur, can we recover 
the rubber? Here lies an attractive problem for chem- 
ists and inventors. Because the shoes, tires, hose, 
belting, water-bottles, and other types of rubber goods 
are partly oxidized, somewhat hardened, broken, and 

88 




Courtesy of The PhiUdtlphia Rubber Works Co. 

VULCANIZED RUBBER SCRAP IN THE YARD OF THE RECLAIMING FACTORY 




Courtesy of The Philadelphia Rubber Works Courtesy of The Philadelphia Rubber Works 
Co. Co. 



RECLAIMED AUTOMOBILE TIRES 



RECLAIMED RUBBER BOOTS AND SHOES 



RECLAIMING WASTE 89 

impregnated with sand, the enterprise is difficult. 
Where the tire has rusted against the metal rim, it 
contains cakes of hard rust. The scrap-pile is cer- 
tainly unattractive. 

At the beginning of this scrap industry, your old 
tire case is sold to the dealer at about half a cent a 
pound. He throws it into his back yard. After he 
has accumulated enough of them, a junk dealer comes 
along and buys these old tires from him. What fun 
it used'to be to gather old junk and trade with the ped- 
dler ! In the back country he was an integral part of 
life. He came about with his load of pots, kettles, 
pans, and brooms, and traded with us for the old rags, 
old gum shoes, and other used-up products, which he, 
as in the present day, sorted according to grades that 
he knew would have more or less market value. 
Finally the junk was shipped to the dealer who handled 
larger quantities; he, in turn, sold it to the factories, 
where it could be worked up into new products. In 
the same way our old hose, our tires, and our rubber- 
ized ^hoes are collected now. The business of buying 
rubber scrap and selling it to the reclaiming mill is one 
of considerable proportions. 

In a consideration of what to do to bring this rubber 
into usable condition, we are at once faced with a 
fundamental fact: most rubber articles contain cot- 
ton fabric in some form, others contain wool, and 
a few, linen. It is a relatively small proportion of the 
total tonnage that is free from fabric of any kind. 
Now, this fabric is weakened by the service it has 
undergone: in many cases, it has been wet and is 
partly decayed. It therefore has little value as fabric 



90 THE REIGN OF EUBBER 

or as cotton. In any event, whether it is good or bad, 
the fundamental problem is to separate the vulcanized 
rubber from it. The first operation necessary before 
these old articles can be put through any process, is 
to free them from foreign materials, such as sand 
and metals. Rubber mixtures must be clean and free 
from any hard materials. 

Consequently, in the reclaiming factory all material 
is first sorted into classes, such as tires, shoes, and hose. 
After sorting, each of them is finely ground. In the 
course of this fine grinding, which consists of two or 
three separate steps, the tire is passed over screens 
and over a piece of apparatus known as a magnetic 
separator. Here the slow-moving ground mixture of 
vulcanized rubber and fabric is allowed to drop in close 
proximity to a magnet, which deflects the iron particles, 
causing them to fall off by themselves, and freeing the 
rubber from the metal. 

The next step is one that has to do primarily with 
the removal of fabric. In the old days, each little 
rubber factory utilized what scrap came to it in its 
own way. It was difficult, if not impossible, to re- 
move fabric except by the so-called mechanical method. 
This removal was accomplished by grinding the rubber 
and blowing the fabric in finely-divided form out of 
the mass by means of an air-blast. The rubber was 
then subjected to the action of live steam at relatively 
high heat; the resulting product became known as 
'* shoddy. '^ This process left much to be desired. In 
the first place, because more or less ground rubber 
adhered to the particles of cotton and were blown 
away with it, the yield was low. In the second place, 



RECLAIMING WASTE 91 

some of the fiber always remained with the rubber 
and accordingly made its appearance in the finished 
product- In other words, the * ' shoddy" was not clean, 
and it was not much more than a filler. 

The first attempts at the use of old rubber are said 
to have been made many years ago. From 1865 to 
1870 but few people used old rubber. One company 
sent old shoes to the women in the country, who tore 
them apart by hand. They were paid by the pound for 
all clean rubber that could be stripped from the cloth 
in the shoes. At this time Austin Day of Ansonia, 
Connecticut, commenced to grind rubber, using at first 
car springs and afterward old shoes. 

Since in 1871 there was a demand for rubber free of 
fiber, E. H. Clapp hit upon the method of subjecting 
the ground material to an air-blast, the process separat- 
ing fiber and rubber. For several years this method 
was used. A number of men, though, tried to free the 
rubber from fiber more completely. Much secrecy sur- 
rounded factory practice. Rubber men, like snails, 
preferred their shells ; therefore who really discovered 
first the acid process may never be known. But it 
takes more than dreams and secret chambers to bring 
about commercial results. 

Lieutenant-Colonel Chapman Mitchell, a younger 
brother of the eminent physician and author, S. Weir 
Mitchell, after the Civil War went into the sugar busi- 
ness with Harrison, Havemeyer & Co., in Philadelphia. 
He had a keen perception. Accosted in the street one 
day by a friend, he was handed some uncured mackin- 
tosh clippings. Could he get the rubber back without 
injury? He saw a future and experimented, and a 



92 THE REIGN OF RUBBER 

new industry in the reclamation of rubber waste was 
born. This was in the early eighties. The finely 
ground mixture of rubber and cotton was immersed 
in dilute sulphuric acid and steam was blown into it 
through lead pipes, the steam warming it to the tem- 
perature which permitted the acid to attack and destroy 
the cotton. As the chemist would say, his process hy- 
drolyzed the cellulose into a form soluble in water. 
After the cotton was destroyed, the entire mass was 
removed into a wooden circular tub or washer with 
a large rotating wooden wheel in the middle, so de- 
signed as to permit the wheel to churn the mixture in 
water. After it was partially washed in this big vat, 
the entire mass was allowed to flow down an inclined 
wooden chute called a riffler, which contained cross- 
pieces or baffles about two to four inches in height 
and spaced about a foot apart. The heavy particles of 
sand subsequently removed, would collect against these 
slats; while the rubber would run on down the riffler 
into a settling tank. This was a sort of adaptation 
of the metallurgical ore-washing methods. 

After this washing process the rubber was in a con- 
dition of relative fineness, although it was still not fit 
for use; for it was firm, tough, vulcanized rubber, 
free from cotton. The acid process part of it, there- 
fore, was simply a cotton remover. Consequently, 
the rubber men conceived the idea of placing the 
rubber in trays, in a large open cylindrical tank, 
about six feet in diameter and twenty-five feet long, 
made of heavy boiler-plates and known as a devulcan- 
izer. When the rubber was put in these trays or 
placed in the devulcanizer in mass, steam was forced 



RECLAIMING WASTE 93 

into the tank. The rnbber was heated usually to 
a temperature around 300° Fahrenheit and for a 
length of time depending upon the type of scrap to be 
heated. Frequently oils, to assist in the process, were 
mixed with the vulcanized rubber before placing it 
in the devulcanizer. The action of the high tem- 
perature served to soften the rubber. There was no 
removal of sulphur: in point of fact, vulcanization 
went on a little further; but in the presence of steam 
and oir, the rubber became plastic enough to permit 
its final mixture with fresh rubber. In time, devulcan- 
izing usually lasted about twenty-four hours. After 
devulcanization the rubber was removed, dried in air 
driers, massed on a mixing mill, and thus prepared for 
reworking. 

An acid process from which nothing ever came had 
been patented in 1863 by C. H. Hayward and D. E. 
Hayward of Massachusetts. Colonel Mitchell, how- 
ever, made the process work, and continued in the in- 
vention of apparatus until 1889. He instituted a com- 
mercially efficient process and organized an industry; 
for his company, the Philadelphia Eubber Works, was 
the first commercial enterprise which had exclusively 
for its purpose the recovery of rubber in the form of 
the usable product that we call reclaimed rubber. 

Because the Mitchell method was particularly applic- 
able to the treatment of scrap in a relatively low state 
of vulcanization and containing no free or uncombined 
sulphur, it was effective with old boots and shoes. 
The soundness of the process is evidenced in the fact 
that even to-day it is still the standard method of 
treating boot and shoe scrap. But since hose, belting, 



94 THE EEIGN OF RUBBER 

and tire scrap are more highly vulcanized and in addi- 
tion contain varying but always appreciable quantities 
of free sulphur, this method leaves much to be desired. 
It was not until the development of the Marks proc- 
ess, the patent for which was issued in 1899, that it 
was possible to obtain an acceptable product on the 
devulcanization of these grades of scrap. Before this 
date, mechanical scraps and tires were of virtually no 
commercial value. 

Arthur H. Marks invented what we to-day know as 
the alkali process for reclaiming, the most advanced 
step that had been taken or that has since been taken in 
making old scrap useful in rubber mixtures. His proc- 
ess consisted in subjecting the ground rubber waste 
when submerged in a dilute alkaline solution, as for 
example a 3 per cent, solution of caustic soda, to the ac- 
tion of heat at a temperature from 344° to 370° Faren- 
heit for about twenty hours, while the entire mass was 
contained in a closed vessel. The finely divided waste 
being placed in a large horizontal tank within which 
paddles or other stirring apparatus rotated, the ground 
rubber with its cotton fiber was constantly agitated in 
the presence of the caustic soda solution, heat being 
supplied from a hollow jacket outside the inner con- 
tainer. After about twenty hours of heating, the en- 
tire mass was ''blown off," as the practical men say, 
into a large washing vat, where it was washed in run- 
ning water, the overflow being screened to prevent the 
reclaimed rubber from running away. The cot;ton, 
made into water-soluble or hydrolyzed form, was 
washed out. The usual processes for removing metals 
and sand by the magnetic separator and the riffler 



RECLAIMING WASTE 95 

were carried out ; and finally, the mass being dried by 
warm air on large screens, it was worked into sheets 
on mills similar to the mixing mills. 

Marks 's first application for a patent was rejected. 
But samples were shown in May, 1889, to the examiner, 
who recognized that something different had been pro- 
duced — at least, something different from the prod- 
uct of the Hoff er process of ordinary boiling in caus- 
tic soda solution, for the plasticity of the rubber had 
been restored. In the Marks process the combined 
sulphur is not removed, but a change has taken place. 
A certain relation of the combination of sulphur and 
rubber constitutes vulcanized rubber, a material that 
is tough and elastic, not plastic. After vulcanized 
rubber has gone through the Marks process, this tough- 
ness disappears and plasticity returns; some funda- 
mental change has occurred. 

By this process, reclaimed rubber, for the first time, 
came to be, under the same conditions, similar in char- 
acter to crude rubber. It was plastic on the rolls; 
the combining ingredients would absorb readily; it 
would vulcanize easily with sulphur. It over- vulcan- 
ized and under-vulcanized as crude rubber did. 

The differences between the reclaimed rubber from 
the acid and from the alkali processes are great. Re- 
claimed rubber that has simply been made soft by heat- 
in, as in the acid process, possesses two great disadvan 
tages : small traces of acid, which cause rapid deterio- 
ration, now and then are left in the rubber ; the tensile 
strength and other physical properties are poor. 
The alkali-reclaimed rubber is strong. It mixes 
well with crude rubber. For many purposes, it 



96 THE REIGN OF RUBBER 

possesses all the necessary properties of crude rubber ; 
for other purposes, it is vastly better than crude rub- 
ber. Owing to a slight alkaline character that adds to 
the length of life of the rubber mixture, it has an ad- 
vantage. Thus has developed reclaimed rubber, no 
longer shoddy. 

Chemists and inventors, trying to reverse the vul- 
canization process, and attempting to split off the sul- 
phur atoms in the vulcanized rubber molecules, called 
the process ' ' devulcanization. " 

One could scarcely wade through the mass of patent 
literature. There have been many hundred patents 
taken out on different modifications of the alkali proc- 
ess alone. Numerous other substances have been 
and still are used in connection with it, to soften and 
give other valuable properties to the resulting mixture. 
But the basic principle has never been modified and 
is to-day the one process by which the greatest ton- 
nages of rubber scrap are reclaimed and made usable. 

Extremely interesting are the methods by which men 
have attempted to dissolve vulcanized rubber in va- 
rious solvents in order to remove the sulphur. I have 
in front of me a list of 156 different substances that 
have been tried, either to dissolve or withdraw the sul- 
phur; they have all failed, and to-day the removal of 
sulphur from vulcanized rubber is probably one of the 
great unsolved problems in the rubber industry. 
Perhaps some of these processes do definitely take the 
sulphur out ; but when the sulphur is all removed, the 
substance left is not rubber but an oil. Rubber is so 
complex, its affinity for sulphur is so strong, that any 



EECLAIMING WASTE 97 

known reagent powerful enough to remove the com- 
bined sulphur makes the rubber unfit for commercial 
use. 

The development of the Marks process resulted in a 
large increase in the use of reclaimed rubber by rub- 
ber manufacturers. By research in the last twenty 
years and by perfecting a product that performs a def- 
inite function in the rubber compound, the reclaiming 
industry has eliminated shoddy. Eeclaimed rubber 
has brought about a saving in mixing time and costs 
and also a decrease in the time of cure. That its use 
is fundamental in the manufacture of rubber goods has 
been clearly demonstrated in the last year by the fact 
that the production of reclaimed rubber has been in 
approximately direct ratio to the production of the 
classes of goods in which it has been used. The in- 
dustry to-day rests upon the Mitchell patent and the 
Marks patent. Scores of other patents have been 
granted, but the processes have lacked some essential 
feature; either they were too expensive, or the agent 
used caused the rubber to deteriorate, or the resultant 
product was not so good as that already on the mar- 
ket. This does not mean, though, that future develop- 
ments may not be as revolutionary and sound as the 
two patents already mentioned. 

For the year 1921 the amount of crude rubber used 
in the United States was 345,599,000 pounds, and of re- 
claimed rubber, 76,508,000 pounds. It is an article of 
tremendous importance and necessity in our economy. 
There is no question of its value ; articles made from 
it age well. Like any other material used in this com- 



98 THE REIGN OF RUBBER 

plex and intricate industry, though, reclaimed rubber 
is one that requires a knowledge of it and of the pur- 
pose for which the resulting article is intended, in 
order to make its use justified. Even raw rubber 
must be used with some degree of care. 

Reclaimed rubber, therefore, plays a large and val- 
uable part. Just stiff enough when in an unvulcanized 
condition, it makes manufacturing of many articles 
more easy. Reclaimed rubber is not used where the 
maximum tensile strengths are required, any more 
than pure crude rubber alone is used where toughness 
or resistance to abrasion are required. For the tough, 
resisting service in a rubber heel, in footwear, in rub- 
ber bumpers, in wire insulation, in carriage cloth, re- 
claimed rubber serves, and serves well. 

Many people seem to feel, usually without a knowl- 
edge of the facts, that reclaimed rubber is not a val- 
uable material for use in rubber mixtures. If it were 
not used, there would be a tremendous waste that rub- 
ber users should not sustain. 

If this little story frees the reader's mind from any 
idea that reclaimed rubber is something inferior, it 
would be well. Reclaimed rubber is not inferior ; it is 
just different. It is true that one can make inferior 
products from the best of materials; therefore in the 
handling of reclaimed rubber, intelligence is required. 
That during the period of low-priced crude rubber so 
large a tonnage of reclaimed rubber has been used is 
one of the best arguments in favor of its value and 
quality. 

The utilization of scrap rubber through reclaiming 
Is an economic achievement. 



CHAPTEK VII 

THE CHEMISTRY OF RUBBER MIXTURES 

This is a chapter of details. But chemistry is a 
science of details, of little things, of explanations. 

In Malaya we could go into the orchard and gather 
a quart of milk from a rubber-tree, and then bring it 
back to the laboratory and ask the chemist to look it 
over. True to the habits of his kind, he would say, 
''I know what that is, and how it is put together." 
He would know only some facts and theorize on the rest. 

As it runs out of the trees, the latex is a milky fluid 
consisting of water in which are suspended minute 
globules of rubber. These globules are solid, not 
liquid. Very fine in subdivision, they measure from 
five ten-thousandths to three ten-thousandths of a milli- 
meter. It is stated that they are so numerous that 
one gallon of latex contains more than two hundred 
billion of them. If we were to lay out these little glob- 
ules side by side, we should find that those in one 
gallon would make a minute rubber thread 372 miles 
long. When observed under the microscope, they seem 
to be somewhat irregular in shape. Since they are 
solid, we term the latex a suspension of solid particles. 
If the rubber were liquid, we should call the latex an 
emulsion. Milk as it comes from the cow is an emul- 
sion. 

99 



100 THE EEIGN OF RUBBER 

When the chemist analyzes the latex, he discovers it 
to contain, on the average 28 per cent, of the chemically 
pure rubber; resins, which are substances soluble in 
the chemical known as acetone, 2 per cent.; mineral 
substance from 0.3 to 0.7 per cent.; components con- 
taining nitrogen, which the chemist calls by the general 
name of proteins, 1 to 2 per cent. ; sugars dissolved in 
the water of the latex, 1.1 to 2.3 per cent. ; and water, 
about 60 per cent. From the latex may be obtained 
30 to 35 per cent, of commercial raw rubber, which 
contains various of these substances. 

Proteins or nitrogen substances play an important 
part in the latex. Modern chemistry has learned how 
small quantites of them assist in the formation of 
emulsions and suspensions because they seem to pre- 
vent the separation of the emulsified substance from 
the water. When you buy cod-liver oil as a medi- 
cine, as most people do at one time or other, you 
see a nice white emulsion. It would be quite 
possible for the druggist to make you an emulsion of 
cod-liver oil by the simple process of shaking together 
the oil and water; but, on standing in the bottle, the 
oil would separate in a layer by itself. Physicians 
have found it wise to give cod-liver oil finely divided 
with water in the form of an emulsion, because it di- 
gests readily. In order to keep the preparation, there- 
fore, from separating into two layers, casein is added 
to it, which has the peculiar property of protecting 
the globules of oil and keeping them away from each 
other. 

Nature has prepared for us a suspension in which 
she has put in a substance, namely, the protein, that 



CHEMISTRY OF EUBBER MIXTURES 101 

permits a high degree of dispersion of these fine par- 
ticles and prevents their rapid coalescence into a layer 
separate from the water. The substances that play 
this part in preventing the coalescence of suspended 
or emulsified globules are known as protective col- 
loids. Different rubber-trees seem to have different 
protective colloids. Because the latex of the Hevea 
tree is very stable, the rubber from it does not tend 
to separate or float to the surface in the form of cream. 
The latex of the African trees and the latex from the 
Central American trees seem to have in them differ- 
ent protective colloids; for, on standing, the rubber 
floats to the top. 

A gallon of latex weighs 8.17 pounds and contains 
from 2.45 to 2.85 pounds of raw rubber. To supply 
the world with 250,000 long tons of rubber requires, 
therefore, in the neighborhood of 224 million gallons 
of latex. The difference in composition between rub- 
ber latex and milk is striking, for the cow has nothing 
like the efficiency in production of the substance most 
desired from it, namely the fat, cow's milk showing 
only 3 to 6 per cent, of butter fat. These two milks, 
the vegetable milk and the animal milk are, therefore, 
radically different. 

On the plantations, it has become necessary to handle 
latex as rapidly as possible, — in any event, to limit to 
certain reasonable and well-known lengths the time be- 
tween its collection at the tree and its coagulation in 
the shed or factory, because as soon as it comes into 
the air from the tree it begins to decompose and to be 
acted upon by bacteria. Coagulation, the change that 
is required chemically in the latex, is the alteration of 



102 THE REIGN OF RUBBER 

the protective colloid. The addition of acids changes 
the latex in such a way that the proteins are no longer 
able to prevent the globules of rubber from running to- 
gether. The first step in the chemical change of latex 
is to add acetic acid in dilute solution. It is used 
in dilute solution because the quantity of protective 
colloid is small and but little acid is required to alter it. 
Strictly speaking from the chemical point of view, the 
nature of its alteration is unknown. It is evident, 
though, that acetic and other acids will cause coagu- 
lation. 

We know that when latex is allowed to stand it grad- 
ually becomes acid from the action of bacteria on the 
proteins; just as when a glue and water solution is 
allowed to stand, it changes to acids through the 
action of bacteria and fungus growth. By any kind 
of coagulation, though, the rubber itself is not changed ; 
the little particles that were held apart in the water 
solution simply mass together. 

If latex is allowed to coagulate spontaneously, a dis- 
agreeable odor develops, which persists until vulcan- 
ization. When coagulation occurs by acetic acid, how- 
ever, the rubber is odorless. Although other acids, 
such as formic acid and sulphuric acid, have been used, 
more than 95 per cent, of the raw rubber is now 
prepared on the plantations by the use of acetic 
acid. It in no way injures the quality of the raw 
rubber. 

Let us now turn to the raw rubber itself and exam- 
ine the facts that chemists have learned regarding its 
characteristics and properties. The first and most im- 
portant one is the variety of substances contained in 



CHEMISTRY OF EUBBER MIXTURES 103 

it. Rubber itself, free from these substances, is a hy- 
drocarbon. An interpretation of this chemical term 
means that it is composed of only the chemical ele- 
ments carbon and hydrogen. Raw rubber contains 
from 92 to 94 per cent, of the rubber hydrocarbon. Be- 
sides this, it contains moisture, mineral substances, 
resins, — which are simply a variety of chemical in- 
dividuals soluble in acetone, — and the proteins. The 
composition is about the same as that of the latex, with 
the water and the ingredients dissolved in the water, 
or serum, removed. 

In the laboratory the chemist, who with beaker and 
combustion furnace analyzes the hydrocarbon, finds it 
to be made of five carbon and eight hydrogen atoms. 
But there are several other hydrocarbons that show 
the same constituents on analysis. The rubber hydro- 
carbon is a distinct one. Therefore he has come 
to believe that several of these CgHg groups are united 
physically (he says * 'polymerized"), and he expresses 
the composition (CgHs)^. 

But the chemist is a singular fellow. He has learned 
that the terpenes, of which turpentine is one, have a 
composition CioHig. So he calls rubber (CjoHie). 
Among his technical friends, he goes further and 
draws a picture of the hydrocarbon, in which the ex- 
act relation of each element to the other is shown. 
Since the chemist loves these pictures, we shall leave 
them to him. They belong to the most intricate field 
of organic chemistry, and the rubber structure to the 
most intricate of them all. 

Rubber may be made artificially by heating the oil 

isoprene." The chemical process, which consists 



(< 



104 THE EEIGN OF EUBBER 

in the addition of one molecule to another, forming a 
succession of these groups linked together into a ring 
of uncertain dimensions, we call ''polymerization." 
How far the chemical composition, the state of poly- 
merization, or the state of aggregation of the poly- 
merized masses, affects the properties of crude rubber 
as we know them, and how far the hydrocarbons from 
trees of various ages differ chemically and physically, 
are all unknown phases of an interesting problem. 
We do not know the part played by mineral substances 
or the exact condition of the nitrogenous matter, al- 
though the proteins have a most important influence 
upon the characteristics of the rubber. 

The other substances in raw rubber after coagulation 
are not deleterious impurities. They are of wonder- 
ful advantage by assisting in resistance to oxidation 
and by helping in vulcanization. 

To determine the percentage of acetone-soluble mat- 
ter, much study has been done by some chemists in the 
analysis of rubber. Eubber from different botanical 
species varies largely in resins. The plantation rub- 
ber coming from the Hevea tree seems to produce the 
smallest amount of any. The Ceard rubber, the Ficus 
rubber, that is, those from Central America and Af- 
rica, on extraction in acetone yield resinous matter as 
high as 7 to 10 per cent. The guayule rubber shows 
20 per cent, of a liquid resin. Lower grades, such 
as the scrap, the rubber that has fallen upon the 
ground, and those grades that have been allowed to dry 
in the bright, hot sunlight, seem to have decomposed 
a little ; as a result, the amount of substance to be ex- 
tracted by acetone has increased. The rubber resins 



CHEMISTRY OF RUBBER MIXTURES 105 

are highly complex, and whether they are the original 
source of rubber in the tree or whether they have been 
produced from the rubber we do not know. Probably 
to-day the '* acetone extract" is the one reasonably re- 
liable means of determining the botanical origin of 
different grades, and the fresh from the deteriorated 
rubber; although the control of quality in a finished 
article can be carried on irrespective of the origin of 
the rubber. The amount of resin extracted by acetone 
is not, as some have believed, a guide to the quality of 
a vulcanized rubber mixture. 

A chemical property of the rubber hydrocarbon is 
unsaturation. It adds directly halogens, halogen 
acids, sulphur, and sulphur chloride, as well as certain 
other substances. 

The story of synthetic rubber has been much dis- 
cussed. Artificial rubber is well-known. During 
the World War much work was done upon it in Ger- 
many, where considerable quantities were produced; 
but it was not the same hydrocarbon as that derived 
from the tree. It was a close relative, known as methyl 
rubber. But the tires and other soft rubber articles 
made from it were decidedly inferior in service. It 
was, however, valuable in hard rubber or ebonite. 

After its coagulation, one can think of rubber as a 
body made up of innumerable round globules of rub- 
ber in the form of a sort of microscopic mass of fine 
shot, each of which is surrounded by a thin film of pro- 
tective colloid, the protein substance. Thus, raw rub- 
ber has a structure. It is not like glass, which is homo- 
geneous; not like leather, which is a mass of fibers; 
or like wood, which is a mass of short, thick fibers. 



106 THE EEIGN OF EUBBER 

The probability of this structure is interestingly 
proved by the action of rubber when it is softened or 
masticated, as we call it, on a mixing mill. If our 
theory be correct, some of the toughness of rubber in 
its raw "state is due to the harder nature of the sur- 
rounding protective colloid. The use of this term, 
protective colloid, when one is speaking of rubber in 
the mass is not exact ; for it really is a protective col- 
loid only when the rubber is dispersed through the 
latex. Nevertheless it still surrounds the particles of 
rubber. These proteins are probably stiff like glue; 
because when masticated on a mixing mill, the rubber 
becomes softer from the breaking up of a certain 
amount of this structure. After prolonged masti- 
cation, it is not so tough as before. 

The rubber, when mixed, is passed through a ma- 
chine known as a calender in such a way that it issues 
in the form of a thin sheet. Even after vulcanization, 
the rubber is found to show a difference in strength in 
the direction of the passage through the calender from 
that at right angles to it. For years the rubber man 
has observed this property, which is kno^vn as '' grain. '^ 
It is quite possible that the little rubber particles are 
stretched during the process of ^.alendering, so that 
we may imagine them in the form of elongated fibers 
very minute in size, rather than as little spheres. 
Since they probably overlap each other in somewhat 
the same way as fibers of cotton during the twisting 
of cotton fiber into thread, one may readily picture 
them a series of little rubber threads, naturally tougher 
in the direction in which the fibers have been stretched. 

In another way we have proved that there is a struc- 



CHEMISTRY OF RUBBER MIXTURES 107 

ture in rubber, which structure is changed and broken 
by the process of mastication. Raw rubber, in a sense, 
does not dissolve in solvents. One may say, rather, 
that the solvents dissolve in rubber. If a piece of 
rubber is allowed to stand several hours, for instance, 
in benzol, in gasoline, or in carbon bisulphide, it swells 
to several times its original size. The solvent has, 
therefore, penetrated and dissolved in the rubber. 
When, Jaowever, in the regular course of cement mak- 
ing, the rubber is beaten or stirred so that mechan- 
ical action is applied upon it, a cement is obtained 
which is really a distribution of the swollen and soft- 
ened rubber in the balance of the solvent that has 
been used; that is, a colloidal solution has been ob- 
tained. The difference between a colloidal solution 
and a true solution lies in this fact; a true solution, 
such as salt in water, is one in which the solid has 
passed into the liquid in such a way that the proper- 
ties of the solution are homogenous. 

When we make this colloidal solution in benzol, us- 
ing only 2 per cent, of rubber that has never been 
passed through between the rolls of a mixing mill, and 
compare that with a liquid of the same strength but 
which has been softened or masticated' by a mixing mill 
for about twenty minutes, we observe a distinct differ- 
ence. The solution that contained unmasticated rub- 
ber is thicker and more viscous than that containing 
the masticated rubber. This has led to a belief in raw 
rubber structure, which structure has been broken 
down by mastication, so that the little films of pro- 
tein are broken up and distributed into the rubber 
mass. Just what the structure is, what it means, and 



108 THE EEIGN OF EUBBBR 

how to change it, are problems yet to be solved by the 
research chemist. 

After all, what is vulcanization? Ever since the 
discovery of the process, chemists have worked upon 
this question. There are numerous theories. One 
thing we do know, however, that sulphur in some way 
actually combines with the rubber molecule. Rubber 
has an affinity for sulphur ; and once it has taken sul- 
phur on, there is no divorce court known that can 
separate them. Probably divorces never leave the 
parties thereto in just the same mental state; there- 
fore, while by drastic chemical methods sulphur has 
been removed from rubber, the rubber is never the 
same in physical properties as it was before its union 
with sulphur. When only about 2 per cent, by weight 
of sulphur is added to rubber, it serves to produce a 
soft, strong, stretchy composition. During a study 
of the basic principles of vulcanization, when a sample 
of rubber containing 10 per cent, of sulphur was 
heated even for a long period of time, all the sulphur 
did not combine. Some of it remained as free sul- 
phur. Investigators analyzed samples regularly over 
a period of several hours, and found that the sulphur 
combined with the rubber steadily. There is no chem- 
ical compound formed during the vulcanization of soft 
rubber ; the process is continuous. The amount of sul- 
phur that enters into combination with rubber in- 
creases with time and rise of temperature; when the 
time and temperature are constant, the amount of sul- 
phur entering into combination with rubber is depend- 
ent upon the quantity of sulphur originally present. 

Once it was believed that sulphur did not combine 



CHEMISTRY OF RUBBER MIXTURES 109 

with rubber until the temperature had passed the melt- 
ing point of sulphur ; but this was definitely disproved 
a few years ago by a chemist who permitted a mix- 
ture of rubber and sulphur to stand at relatively low 
temperatures, one sample at 122° Fahrenheit, over 
periods of days up to eighty. He found the same 
regular combination of sulphur with the rubber. So 
vulcanization does go on at ordinary temperatures, 
but slojvly. 

When small amounts of about 3 per cent of sulphur 
are combined, as we say, with rubber there results 
the soft rubber of commerce. During the time of 
heating, while the essential process of vulcanization 
occurs, all the sulphur is not combined; there is an 
excess called ''free sulphur.^' Shortly after the rub- 
ber is removed from the mold at the end of the vul- 
canization, the color at the surface is that of the 
mixture itself. When the rubber stands for a little 
while, however, an interesting change takes place; 
for this excess sulphur, or ''free sulphur,'' begins 
to crystalize and separate itself from the rubber. 
Probably dissolved in the rubber during vulcan- 
ization, on cooling and standing it separates. At the 
surface, we find it coming out in the form of a gray 
powder called "bloom." 

Essentially all rubber articles show bloom, or ' ' sul- 
phuring up," on the surface. To be sure, there are 
some of them such as boots and shoes and colored 
water-bottles wherein a freedom from this gray powder 
is desired. It is very difficult for the rubber chemist 
so to design his composition that bloom will not occur. 
In doing this, in order to combine all the sulphur, he 



110 THE REIGN OF RUBBER 

uses the minimum quantity and vulcanizes for as long 
a time as quality permits. Even then, there is a small 
quantity of uncombined sulphur that may, under par- 
ticular conditions, come to the surface as bloom. 
The sulphur crystallizes also inside the mixture. A 
sheet of rubber cut after standing twenty-four hours 
shows under a microscope beautiful crystals of sul- 
phur. The photograph shows this internal crystal- 
lization. Bloom, though, does no harm. In point of 
fact, up to the limit of our knowledge at the moment, 
the strongest, toughest articles show bloom. Some 
day, however, we may find means of overcoming it; 
although it is not deleterious. It is singular, too, how 
sulphur, which was a yellow powder mixed into the 
rubber in the beginning, comes out on the surface as 
a gray one. 

Sulphur is one of those interesting chemical ele- 
ments that seems to have the power of existing, like 
Dr. Jekyll and Mr. Hyde, in more than one form. The 
chemist calls them allotropic forms. Interested in 
what the form is, the crystallographer finds that each 
is a different crystal, with edges and faces variant. 
The rubber man finds the yellow sulphur that he 
originally mixed comes out on the surface as a gray 
bloom; the casual notice of that change is about the 
extent of his interest. 

The time and temperature of vulcanization are ,the 
two necessary outside factors giving the proper qual- 
ity to the rubber composition. The rubber man must 
observe these in just about the way the cook must 
observe the time and temperature of cooking different 
cakes. When the young housewife puts the wrong 



CHEMISTRY OF RUBBER MIXTURES 111 

substances or the incorrect proportions into her bis- 
cuits, she bakes soggy ones. If she leaves them in the 
oven too short a time, they are underdone. Likewise, 
if the rubber man removes his mixture from the press 
and the mold too soon, he finds the rubber to be weak, 
somewhat sticky, or, as he calls it, ' ' undercured. " If 
he leaves it in the right length of time (there is a large 
leeway usually), he finds it strong, not tacky, and resil- 
ient. If he leaves it in too long, it becomes like over- 
done roast beef, dry. On breaking, it is found to be 
short, that is, it breaks at a shorter elongation than it 
should. He calls it * * overcured, " or he says it is 
burned. By long, sad experience, he has also learned 
that it does not age well, but gradually becomes harder 
and harder, taking on oxygen from the air with much 
greater rapidity when over-cured than when either 
under or correctly cured. The time and temperature 
of cure for each composition, or the adjustment of the 
composition to cure at a time and temperature for 
some factory practice, is one of the most essential of 
the rubber chemist 's duties. 

There are wide and, to the manufacturer and con- 
sumer, vitally important differences in physical prop- 
erties between under-cured, properly cured, and over- 
cured rubber articles. Still we have as yet only the- 
ories of a general character to explain the nature of 
these products of vulcanization. The amount of com- 
bined sulphur, when expressed as a percentage figure 
in terms of rubber as 100 per cent., is -known as the 
coefficient of vulcanization. No chemical individual 
of the rubber hydrocarbon and sulphur has been iso- 
lated from soft, vulcanized rubber mixtures. 



112 THE REIGN OF RUBBER 

When a large excess of sulphur is used in a mix- 
ture, addition goes on up to a maximum of 32 per cent, 
of combined sulphur; and there results the only chem- 
ical compound that yet has been isolated — a mono-sul- 
phide CsHgS, or, as usually written, CjoHieSa. It is, 
in the laboratory, a brown, dry powder. In the factory 
and in commerce we know it as hard rubber or ebonite, 
used in battery jars, sheets, fountain-pens, and the like. 
It is highly resistant to the action of chemicals. Around 
hard rubber has developed a sort of separate industry, 
to be discussed in a later chapter. It is a rubber in- 
dustry, to be sure, but an industry wherein stiffness, 
strength, freedom from action of chemicals, and a high 
degree of resistance to penetration by electrical 
charges are required. 

Many discussions have arisen between two camps of 
chemists; those who expound the sulphur absorption 
theory of Ostwald and those who stand by a chemical 
theory. The great rubber chemist Weber was an ex- 
ponent of the chemical theory. Chemists to-day ad- 
here to a combination of a chemical and physical the- 
ory as most reasonable for the explanation of vulcan- 
ization. The fact that no compounds have yet been 
isolated in the soft rubber range of vulcanization is no 
reason for us to believe that a purely physical theory 
alone will account for it. Carl Otto Weber will ever 
remain in the minds of rubber chemists as the most no- 
table leader. Born in 1860, of Grerman-Scotch ances- 
try, he studied chemistry in Germany and migrated to 
England, where for some years he was a managing 
chemist in a rubber factory. A prolific contributor to 
technical literature, an indefatigable research chemist, 




\ ,-. .. -^ / - «. ' x *T^ • .• • s" • 

, '«^- • . ■So:, <» '^ ■■<«»•*, • ? s 

» • . "■•<•- .*..«' ^ - * ^''•. ' * 




Courtesy of The New Jersey Zinc Co. 

ZINC OXIDE 



CARBON BLACK 



PHOTOMICROGRAPH OF BARYTES, ZINC OXIDE, WHITING, AND CARBON BLACK, COMMONLY 
USED IN RUBBER MIXTURES. MAGNIFIED 1500 DIAMETERS 



CHEMISTRY OF RUBBER MIXTURES 113 

he became a leader in things rubber. He finally came 
to America, where he died in 1905. Weber may truly 
be called the father of rubber chemistry. 

Besides the one described, there are other methods 
of vulcanization. Shortly after a knowledge of sul- 
phur or ''hot" vulcanization was obtained, Alexander 
Parkes, a chemist of Birmingham, England, having 
seen the result of Hancock's work and his patent spe- 
cifications, immediately went to work and tried the 
effect upon raw rubber of all the compounds of sulphur 
that he knew. At length, in 1846, he succeeded in ob- 
taining a vulcanized rubber by immersing a sheet of 
raw rubber in a mixture of 100 parts carbon bisulphide 
in which had been dissolved two and one half parts of 
sulphur chloride. After immersing it for about one 
and a half minutes to three minutes and drying it, he 
found his material to be stronger than it had been 
and resistant to heat and cold. Thus the discovery of 
vulcanization by a different method was made known. 

Chemists have found by further study the significant 
fact that sulphur chloride, which is expressed chem- 
ically S2CI2, like sulphur, combines with the rubber 
molecule. Even though the results are essentially the 
same as in the first process, because of the highly 
corrosive character of sulphur chloride, the use of this 
material has been limited to combination with raw 
rubber into which no other substance has been mixed. 
But that discovery has been important to you; since 
you probably use it when sitting in the dentist 's chair, 
as the rubber dam to keep saliva from moistening the 
cavities that have been opened by the dentist is one of 
its products. The rubber is cured, however, at low 



114 THE REIGN OF RUBBER 

temperature ; that is, the ordinary room temperature. 
No more is known of the real chemistry of this process 
so far as soft rubber is concerned than is known of the 
hot or pure sulphur vulcanization. We do know 
that when an excess of sulphur chloride is used, 
a chemical compound approximating (CioHi6)S2Cl2 
is obtained. This is a dry powder with no valuable 
properties. It corresponds chemically to the product 
obtained in hard rubber. 

In recent years two new processes of vulcanization 
have been developed. One of them was first discov- 
ered by a Russian named Ostromislensky, who discov- 
ered how certain complicated organic compositions, de- 
rivatives of coal-tar, when mixed with rubber and 
heated, cause a stiffening, an increase in strength, and 
a resistance to temperature change quite similar to 
that obtained when sulphur is used. He has not, how- 
ever, succeeded in producing any substances that have 
the tensile strength given by sulphur during vulcaniza- 
tion. The process is interesting from a chemical point 
of view. It may lead us ultimately to a clearer knowl- 
edge of what vulcanization is, although the field is a 
large one and will probably take years for a complete 
solution of its problems. 

Within the last few years an Englishman, S. J. 
Peachey, patented a method of vulcanization at ordi- 
nary temperatures. When crude rubber in a form such 
as sheets, clothing, etc., is treated with sulphur diox- 
ide gas, it is rapidly absorbed into the rubber much as 
vapor of solvents is absorbed. When this absorption 
is complete, the rubber is saturated with hydrogen sul- 
phide. These two gases interact, with the formation 



CHEMISTRY OF RUBBER MIXTURES 115 

of sulphur in a very active or, as the chemist calls it, 
nascent condition. It is so active, in fact, that it adds 
itself to rubber very easily at room temperatures, giv- 
ing thus a process of vulcanization that is different 
from any of the others, although the basic principle is 
that of addition of sulphur to rubber. These processes 
are being worked out in England and, to a degree, 
in this country ; but they have not yet become a large 
factor in our rubber markets. 

The most striking advance in the chemistry of vul- 
canization has been made with the use of organic ac- 
celerators. The first inorganic accelerator was white 
lead, used by Groodyear in 1839. The chemistry of this 
type of accelerator, so far as known up to recent years, 
was that of the old idea of the carrier. Serving to 
attach to itself sulphur, and then letting' go of it, 
white lead gave the sulphur to the rubber in a shorter 
time than the rubber could take it up alone. Without 
knowing exactly the condition in which the sulphur was 
when given to the rubber by white lead, the chemist 
supposed, in any event, that the sulphur was made 
more active by the use of this catalyst. 

With the coming of the organic accelerator, many 
chemists have tried to find out exactly why it acts 
so rapidly. Despite the large number of these organic 
substances, the idea was prevalent for some years that 
only those containing nitrogen were sufficiently power- 
ful for practical use. Thus, the derivatives of aniline, 
or, as it is known to the chemist, aminobenzene, were 
employed, and various more intricate modifications and 
derivatives of aniline. Lately, however, chemical com- 
pounds that contain sulphur have been employed. 



116 THE REIGN OF RUBBER 

These facts have led chemists to search for the cause. 
To make a long story sufficiently short, these investi- 
gators have learned that vulcanization occurs most ac- 
tively when the accelerator first adds sulphur to itself, 
and then separates off the sulphur in a particularly 
active condition. The accelerator with its extra sul- 
phur chemists call a polysulphide. It acts like a dump- 
cart — quickly loaded, quickly unloaded. 

The real chemistry of the properties possessed by 
vulcanized rubber when in contact with oils such as 
benzol, gasolene, or heavier lubricating oils, is not 
known. Raw rubber absorbs these oils and swells; 
vulcanized rubber likewise absorbs them and swells. 
Some substances cause vulcanized rubber to swell more 
largely than others ; and some cause vulcanized rubber 
to shrink. Methyl alchohol, wood alcohol, or grain al- 
cohol will shrink vulcanized rubber slightly. Some 
substances produce no change. The derivative of ben- 
zol known as toluol swells vulcanized rubber slightly; 
benzol swells it to nearly double its size, but car- 
bon bisulphide to more than double. But this swelling 
is the end of the effect ; it is not possible by heating or 
by any other method to make vulcanized rubber into 
a colloidal solution. Oiled roads, therefore, are not 
particularly good for tires. 

In an earlier chapter we have considered powders 
and their effect in rubber mixtures. Why do these 
substances act as they do? It is a most interesting 
question, and one that is probably not yet wholly 
solved. Let the microscope tell its story. An exam- 
ination of the photomicrograph of zinc oxide and some 
other substances used in compounds shows these sub- 



CHEMISTRY OP RUBBER MIXTURES 117 

stances to be very small. It is doubtful whether the 
ultimate particle of carbon-black has ever been seen 
under the microscope. It is probable that the larger 
particles shown are aggregations, and that even the 
smaller ones may be minute aggregations. When the 
microscopist measures these, he observes as closely as 
he can the particle-size expressed in diameters, as 
though these little particles were spherical in shape. 
The diameter of carbon-black is less than two ten- 
thousandths of a millimeter; that of zinc oxide 
is about five ten-thousandths. Other dry pigments 
are all larger in size. Not only do the photo- 
graphs show the particles of carbon-black and zinc 
oxide to be finer in size than those of the barytes, but 
they vary in structure and do not seem to have the 
sharp angles and faces evident in the barytes. Here 
the chemist has made good use of the microscope, as 
you see in the photographs. 

These finer-grained materials may be classed in two 
groups : finely divided colloidal particles and all others. 
Colloidal particles are those of gas-black, zinc oxide, 
lithopone, some grades of clay, magnesium carbonate, 
and many others. The ''all others" include barytes, 
asbestine, whiting, and a large number of mineral sub- 
stances. There is no clear line of division between 
these groups, except in the process of manufacture, 
the size, and the specific action in a rubber mixture. 
After all, rubber, as the consumer gets it, is not a sim- 
ple mixture of rubber, sulphur, accelerator, zinc oxide, 
and carbon-black ; but, to meet the demands of numer- 
ous physical properties required for service in the 
form of shoes, adhesive layers, treads, and belt covers, 



118 THE REIGN OF EUBBEE 

other materials must be used. We have found in re- 
cent years how these materials serve practical pur- 
poses and are not simply cheapening fillers. In point 
of fact, many powders now cost more than crude rub- 
ber. The rule-of-thumb methods are gone from the 
leading laboratories, but the variables are so extended 
that the service test has become the final criterion of 
the value of any mixture. 

While we have developed research laboratories to 
show us why, development departments to show us 
how, testing machinery to give us results, we, never- 
theless, are constantly faced with the question: Will 
rubber age? Rubber is a perishable product. For any 
purpose, a knowledge of the rate of deterioration is 
most advantageous, because the problem is a vital one 
to manufacturer and consumer. Heat, light, oxygen, 
and sulphur play their parts in the tragedy; but, as 
yet, no definite theory to account for the varied rate of 
aging has been proposed. In the vast majority of 
cases, too rapid decay is due to over-cure of the mix- 
ture, or improper conditions of storage. Differing in 
practice from that of the old days, chemists have de- 
termined means of testing the rate of aging. Various 
types of apparatus have been developed, until to-day it 
is possible within a space of two weeks to predict 
fairly confidently the length of life of any given compo- 
sition ; at least, the prediction can be made by compari- 
son with compositions of a known length of life. 

All rubber goods should be stored in the dark and 
kept as cool as possible. Both these factors are under 
the control of the user. Even though the rubber chem- 
ist makes his compositions the best he can, it still is 



CHEMISTRY OF RUBBER MIXTURES 119 

necessary for the consumer to cooperate with him by 
keeping away these two active forces, heat and light, if 
he, the consumer, desires to maintain his rubber prod- 
ucts for the maximum time. How long should they 
remain strong and serviceable? That depends upon 
storage conditions, because over-cure has pretty gen- 
erally disappeared. In hot climates one should expect 
trouble; under temperate and cold conditions, very 
little^ 



CHAPTER VIII 
THE BICYCLE TIRE 

When Nancy Hanks in 1892 trotted a mile in 2:04 
and clipped over four seconds from the best previous 
record, she not only established a mark for horse rac- 
ing, but she earned a place in the hall of rubber fame. 
For the first time in history, pneumatic-tired wheels 
were used successfully on vehicles other than bicycles. 
She drew the bicycle-wheeled sulky. Her performance 
announced to the world that pneumatic tires on wheels 
were speedy. In a few months the steel tires disap- 
peared from sulkies and the solid tires from bicycles. 

As the forerunner of the automobile, the bicycle ex- 
pressed a human desire for faster and more comfort- 
able transportation. The history of the bicycle be- 
gan in Germany in 1816, with the first vehicle upon 
which man rode and propelled himself. A year or so 
later, the old dandy-horse or hobby-horse was de- 
veloped in England and introduced into America. 
The bone-shaker (a descriptive name), driven by the 
feet alone, and steered by hand, was exhibited in 
Paris in 1865. It was a two-wheel velocipede with 
foot cranks and two wooden wheels equipped with iron 
tires. For several years this was quite popular, but 
it was too uncomfortable to serve for long. 

About 1870 C. K. Bradford suggested rubber tires, 

120 



THE BICYCLE TIRE 121 

and so for a time solid, round tires were used. 
By 1877 the tire had evidently given sufficient relief 
from discomfort to warrant the organization of the 
Pope Manufacturing Co., to make bicycles with solid 
rubber tires. Eiders shook themselves upon these 
until 1888, when John Boyd Dunlop of England, in an 
attempt to satisfy the cravings of his small boy, in- 
vented a type of tire that was the first practical ap- 
plication of the pneumatic tire. He had, to be sure, 
been antedated in principle, as he himself admits, by 
several inven-tors, particularly Robert W. Thomson in 
his idea of a carriage wheel as early as 1845. Thom- 
son, an Englishman, wished to make carriages easier 
to draw, noiseless, and more comfortable. He made 
the first single-tube tire of several plies of canvas 
covered with rubber — "sulphurized India rubber and 
each fold connected to the one below it by a solution 
of India rubber." He blew it up with air. The af- 
fair was crude, but the inventor was far ahead of his 
time. 

Dunlop, a veterinary surgeon in Belfast, Ireland, 
unlike Thomson, brought out his idea opportunely ; but 
it might have been neglected, except for the foresight 
of Du Cros, prominent enthusiast in Irish racing. Du 
Cros organized the Dunlop Co., doing much to make 
the Dunlop tire practicable. This is another one of 
these instances where mere invention has not signi- 
fied application. Many inventors are so far ahead of 
their times that their work falls into the discard; and 
it remains for others really to develop* the ideas and 
put them on the market in form for real use and ser- 
vice. That inventor who fits his work to an immediate 



I 

122 THE REIGN OF RUBBER ^ 

Meed and combines it with business acumen and manu- 
facturing facilities is he who makes the greatest suc- 
cess. From Dunlop down to the present, the bicycle 
tire has been continually improved, filling the changing 
needs of service. 

This first Dunlop tire was an outer casing of several 
plies of rubberized canvas, with means of inflation. 
Bound about each of the wheels of a tricycle owned by 
a young son of the inventor, it was held to the rim by 
wrappings of tape. Thus the bicycle tire came into be- 
ing, to fill the needs of youth. It was called the *' pud- 
ding tire" and was generally ridiculed. It was, how- 
ever, faster on the road and more resilient than the 
solid tires of that day. The patents granted resulted 
in the formation then of one of the world's most im- 
portant tire companies, the Dunlop Pneumatic Tyre 
Co., Limited, of England. Living until October 23, 
1921, Dunlop came to see his work and the company 
which bore his name a tremendous success, and to see 
his invention used on millions of bicycles and automo- 
biles. 

Tape wrappings to hold a tire on a felloe did not 
last long enough. To improve them, there came sev- 
eral inventors ; among them. Pardon W. Tillinghast, in 
1892, with a perfected single-tube tire, a valve, and a 
method of attaching the tire to the rim. He had vul- 
canized into the form of an annular ring, an inner tube, 
a supporting layer of fabric, and an outer wear-resist- 
ing cover. He endeavored to improve Dunlop 's tire, 
because he thought the tube would chafe against the 
casing. His invention w^as put on the market under 



THE BICYCLE TIRE 123 

the name of the Hartford Tire, manufactured by the 
Hartford Eubber Co. 

It is stated that the pneumatic tire factory of George 
R. Bidwell Cycle Co., of New York City, in April, 1891, 
turned out the first pneumatic tires on this side of the 
Atlantic. 

Probably the one other patent of most interest is 
that of Thomas B. Jeffery of Chicago, who in 1892 
developed an improvement in form of a specially de- 
signed clincher tire of a double-tube character. He 
worked out new means of securing the tire to the wheel, 
of diminishing danger of puncture, and of preventing 
a leakage of air that would occur with a puncture. 
Even though the prevention of leakage was not highly 
successful, the idea of a clincher rim was quickly taken 
up in cooperation with a Mr. Gormully. The GormuUy 
and Jeffrey tire, or the G. & J., as it was called, was 
for many years one of the most prominent and widely 
used types of bicycle tires. In fact, upon this clincher 
rim principle as almost simultaneously developed in 
France, the original pneumatic tires for automobiles 
were based. Morgan & Wright of Detroit also in- 
vented modifications of value. 

In these years, the bicycle became increasingly pop- 
ular, so much so in fact that many a rubber company 
making tires may oe said to owe its survival in the 
panic of 1893 to the popularity of this means of loco- 
motion. Tire making progressed rapidly in Europe 
simultaneously with development in America. 

In England in 1893 the original pneumatic tire made 
by the Pneumatic Tyre and Booth's Cycle Agency, 



124 THE REIGN OF RUBBER 

Limited, and commonly known as the *'Dunlop" from 
tlie name of the inventor, holds the place of honor. 
Not only this, but the patents had been admitted by 
nearly all the tire makers; and these were paying 
royalty. The 1893 pattern consisted of an air tube 
and an outer cover backed with strong canvas. 
Through the edges of this canvas continuous wire rings 
passed. These rings were smaller in circumference 
than the edge of the rim, but greater than the center ; 
and when the tire was inflated, they rested midway be- 
tween the two and could not slip off. The tire was 
fast, comfortable, and tough. Then there was the 
Scott tire ; and next came the Michelin tire, which was 
secured to a nearly flat rim by steel rings. The Sed- 
don tire was another pattern. Another group of tires 
may be described as the clincher variety, the cover be- 
ing secured to the rim by the pressure of the air. The 
clincher, made by the North British Rubber Co., was 
the originator of this class. There were several 
others. 

The Philadelphia Cycle Show in February, 1893, 
marked a turning point of moment in tire history, for 
there the first cord tire was shown. The inventor was 
John F. Palmer of Chicago, and the manufacturer, the 
B. F. Goodrich Co., of Akron. He attempted to embody 
a principle that secured the closure of any ordinary 
puncture that might occur in the tread. But it did not 
close punctures. Have we ever seen a tire that did? 

Bicycles were soon everywhere. Bicycle racing be- 
came a sport of parts. In Europe, where the automo- 
bile development has not progressed in proportion to 
population so rapidly as in this country, the bicycle 



THE BICYCLE TIRE 125 

is to-day seen upon the public road to a very much 
greater degree than here. In France in 1921 there 
were over 4,000,000 bicycles; in England, about 
5,000,000 ; and in America about 5,000,000. 

The bicycle tire of the single-tube variety is made to- 
day in largest numbers in America; in Europe the 
double-tube predominates. A bicycle tire in the 
United States is simply a tube, round in section and 
circular to fit the wheel, made of several layers of light 
fabric, proportioned to the degree of load that it must 
carry, with an inside layer of rubber to hold air, an 
outside layer of rubber to resist abrasion, and layers 
of rubber between the plies of cotton to hold them to- 
gether, and the whole thing vulcanized in one process. 

If we were to go over into the bicycle tire department 
of any of the several manufacturers, we should find 
a process about like this : Frictioned and coated fab- 
ric to make up the plies giving strength to the tire has 
been previously prepared in the calendar room, where 
compounds are used that experience has proved good 
for the purpose. The rubber inner tube is laid 
upon the bias-cut fabric. These layers are as long as 
the circumference of the tire and as wide as the 
length around the section of it. A little extra is used 
to overlap or splice the edges and ends. The work- 
man now overlaps and sticks the edges of tube and fab- 
ric together from end to end around a -short, curved, 
hickory form, while the fabric lies upon a sheet-iron 
drum. Then he attaches the valve-stem, the form is 
pulled out, and the opening closed. The outside rub- 
ber parts, tread and side wall, are applied in sheet 
form, after which process a drum a little larger is 



126 THE EEIGN OF EUBBER 

pulled over the now formed tire, and air is blown into 
it to press it between the drums. The outer drum by 
a quick motion is pushed along the inner, an action 
which serves to roll the inflated tire between the two 
drums and thus force all parts to stick together. 

The unvulcanized tire is formed in the same shape 
and size in which it comes into the market. It is taken 
to the vulcanizing or curing room, where it is laid in 
a two-part mold or doughnut of metal that has been 
hollowed to the exact size of the outside of the tire, 
the valve projecting out through an opening into the 
hole in the doughnut. The top of the mold having 
been laid on, the mold is put into a hydraulic press, 
where pressure upon the mold closes it. Steam is 
then applied inside the tire, inflating it against the re- 
sistance of the heated mold and causing the rubber to 
flow into the markings that give form to the tread. 
Because of the heat of the steam inside and the heat 
of the mold from the steam in the press plates outside, 
the rubber composition quickly vulcanizes. 

This is the simple method of making a bicycle tire 
composed of square-woven fabric. There are, how- 
ever, bicycle tires of cord construction. The first cord 
tire, the Palmer cord bicycle tire, showed so much 
greater resiliency than the square-woven fabric bicycle 
tire that many a race was won by means of it. It was 
an expensive tire to build, for it was before the days 
of the conception of a loom-prepared fabric made of 
cord. Nowadays, cord bicycle tires are made from 
the same type of fabric, although lighter in weight, 
that we use in automobile cord pneumatic tires. 

There are several different weights : there are those 



THE BICYCLE TIRE 127 

made of heavy fabric, suitable for all commercial and 
utility purposes ; there are medium- weight tires, which 
should be the choice of the average rider who uses 
his machine for general purposes; and there are the 
light-weight tires for the man who wishes to go at 
the highest speed or to enter races. 

Here, the quality of rubber and the construction of 
the fabric make great differences in the resiliency and 
speed. As in the case of all articles, the rubber chem- 
ist designs his compositions each for a particular pur- 
pose ; thus the tread is carefully worked out to give re- 
sistance to abrasion, and the friction or layers of rub- 
ber which hold the plies of fabric together are designed 
to do that particular thing during the life of the tire. 

The bicycle has come into our lives to stay. It is 
a light, convendent little machine, which transports 
people easily and quickly and at the same time gives 
them some exercise. 

But as the boy, so may the man become. The bicycle 
tire prepared the way for the automobile tire. It set 
men thinking, too, about good roads. We owe much 
to Colonel Alfred A. Pope, who in 1893 sent out to the 
newspapers a circular letter urging the people of the 
country to petition Congress for the establish- 
ment of a Road Department and Institute of Road En- 
gineering. He was the pioneer in this country for 
good roads. If the bicycle tire did nothing else it 
stimulated highway construction. 



CHAPTER IX 

THE PNEUMATIC AUTOMOBILE TIEE 

In China there was a horseless vehicle before 1600. 
Vehicles propelled by foot and hand were known in 
Europe in the seventeenth century. A French phy- 
sician made a mechanical vehicle in 1710. Carriages 
with sails were early known in England. The period 
from 1800 to 1835 was a vastly busy one for steam en- 
gineers, and about that time the steam vehicle be- 
came fairly well established in England. 

The old Hancock steam carriage of England, called 
''the infant,^' making regular trips between London 
and Stratford, was a forerunner of the modern in- 
terurban passenger bus. To its inventor prob- 
ably should be given the distinction of making the first 
passenger automobile in the world, because he manu- 
factured for himself a steam phaeton, used extensively 
about London, that was equipped with seats for three 
persons. 

Upon the internal combustion engine and the 
experiments of Daimler, Benz, and Selden the 
automotive industry to-day really rests. All the first 
cars, and particularly the steam ones, lacked strength 
and sturdiness; they jarred themselves to pieces in 
a comparatively short time after being put into serv- 
ice. To be sure, the metals were not so good as 

128 




Courtesy of The B. F. Goodrich Co. 

FABRIC TIRE DISSECTED 




Courtesy of The B. F. Goodrich Co. 

CORD TIRE DISSECTED 



THE PNEUMATIC AUTOMOBILE TIRE 129 

those of to-day, for modern metallurgy is of relatively 
recent development; but the main difficulty lay in the 
vibration caused by bad roads and lack of cushioning. 
True, the use of rubber for cushioning vehicles had 
been planned by Thomas Hancock in England. That, 
though, was before the days of vulcanization; conse- 
quently his idea had no real value. It was therefore 
the discovery of the art of vulcanizing rubber and the 
making of tires from it that made possible the extended 
development of the automobile. 

In 1896 there were but four gasolene automobiles in 
the United States : the Duryea, the Ford, the Haynes, 
American cars, and the imported Benz. They were all 
experimental machines; there was no market, and it 
was 1898 before the first bona-fide sale was consum- 
mated. Alexander Winton, who ranks almost with the 
pioneers from the point of view of experimentation, 
sold a one-cylinder Winton automobile; he received 
payment for it and shipped the car April 1, 1898. 
Curious old things, they would make as much of a sen- 
sation on the road to-day as they did then, but for 
quite a different reason. 

•The next time one of your tires blows out or is other- 
wise incapacitated for service, you might find it inter- 
esting if, instead of passing it on to the junk dealer, 
you would spend an hour in an examination of its con- 
struction. Whether your tire be ''cord" or ''square- 
woven fabric," cut a two-inch section out of it with a 
sharp knife from tread to bead, so that the edges will 
be smooth. Then saw the bead in two with a hack-saw. 
There are three necessary parts of a tire : the casing, 



130 THE EEIGN OF RUBBER 

the tube, and the rim. By common consent the casing 
is called the tire. 

Without regard to the refinements of tire design, 
which may differ slightly with tires made by different 
manufacturing companies, one observes several parts, 
each of which is essential to the use and the service- 
ability of the tire. The bead, which is the part in 
immediate contact with the rim, serves to hold the tire 
in place; without a bead or stiff part at the base of 
the tire, it would, under the strain of driving, quickly 
separate itself from the rim. In the early days 
drivers had many harrowing experiences with badly 
designed, primitive rims and beads that came off, left 
the car, and ran on ahead as though to point the way. 
In general use there are two types of beads : one, the 
clincher; the other, the straight bead. The clincher 
bead was the first type and is hook-like at the base. 
In America it is the common type in three and three 
and one half inch sizes. In Europe it is still largely 
used in all sizes. Later development found in the 
straight bead a better type, which, by virtue of the 
metal strips within the bead, is inextensible ; it cannot 
slip over the rim when expanded under air pressure. 

The straight bead or straight side tire has proved 
itself by tests and experience to be the best one in 
construction and service. This type of tire, other 
things being equal, lasts longer than any other; for 
the stresses and strains set up in the fabric, which is 
the next basic element of tire construction, are less 
irregular when the plies are folded around a straight 
bead than when they are curved as sharply as in the 
clincher type. Europeans will come after a time to 



THE PNEUMATIC AUTOMOBILE TIRE 131 

the more convenient demountable rim with its straight 
side tire. 

In a tire, we depend not alone upon the bead but also 
upon fabric. There are many niceties in the construc- 
tion of cotton thread and the weaving of it into both 
square-woven fabric and cord fabric. Particularly 
must the cloth be processed in the rubber factory in 
such a way as to allow each layer or ply to work har- 
moniously under the bendings incident to service. 
When a thirty-two by four inch cord tire is inflated 
to sixty pounds of air pressure, there is exerted within 
it an outward force of thirty tons. When loaded to 
twelve hundred pounds, it is pressed in nearly three 
quarters of an inch ; and every time the wheel revolves, 
each part of the tire is deflected by that amount. It 
is constantly bent back and forth in service. Wire 
bent this way quickly breaks; but the fabric bends 
over six million times in each ten thousand miles. 

The remarkable increase in tire service during the 
last five years, is due to the scientific adjustment of 
the threads that make up the fabric and cord, as well 
as to the greater resistance of the rubber layers to 
flexion and heat. This rubber layer called ''friction 
and coat ' ' holds the plies of fabric together and at the 
same time keeps them apart so that they cannot rub 
against each other; it is another of the essential ele- 
ments in tire construction. The fabric moves over very 
small distances, yet sufficiently to develop heat. This 
rubber must serve as a permanent lubricant ; not tem- 
porarily, like the oil that is put in between the leaves 
of springs or into the transmission or the differential 
housing, for that can be changed every few hundred 



132 THE EEIGN OF EUBBER 

miles, but permanently, because the rubber in the lay- 
ers between the cords is put in at the time of manufac- 
ture and stays there until the tire is gone. There is no 
other substance yet found that will remain so perma- 
nent as vulcanized rubber under the heat and bending. 
But the cotton is equally important with rubber; it is 
the backbone of the tire. 

The fabric of the so-called square-woven type is 
manufactured by those operations generally used for 
ordinary cotton cloth. That is to say, the fibers are 
twisted into yarn and the yarn into threads, and the 
threads are then woven into cloth upon a loom. The 
threads are of the same size, shape, and twist ; one set 
known as **warp" is interwoven with another set 
called ** filling," and each runs under and over the 
one adjacent to it. Because as the tire bends, these 
interlocked threads wear against each other, the fabric 
tire gives a shorter mileage than the cord tire. A 
study of a tire section or of a piece of fabric shows 
this wavy condition. 

The cord tire is made from thread fabric. The warp 
is constructed of cords of the right number of fibres, 
twisted to the proper size and woven on a loom with 
relatively few filling threads of a light nature to hold 
the cords together in manufacture. Usually there are 
only five filling threads in two inches of cord fabric. 
During frictioning, the warp threads straighten out 
into approximately parallel lines, no one of which is 
in contact with its adjacent partner. In the cord tire 
each cord or layer of cords is separated from every 
other by rubber; in the fabric tire each thread over- 
laps the one adjacent to it. These are the fundamental 




Courtesy of The B. F. Goodrich Co. 

LAYING ON THREAD FABRIC IN BUILDING A CORD TIRE AT THE TIRE BUILDING MACHINE 




Courtesy of The Fisk Rubber Co. 

TIRES READY FOR THE VULCANIZERS, IN THE VULCANIZER ROOM 



I 



THE PNEUMATIC AUTOMOBILE TIRE 133 

differences between cord and fabric tires. The re- 
peated flexing a tire is subjected to is one of the ele- 
ments of wear, indeed a major element, which cotton 
resists and other materials do not. 

In various parts of the tire there are several differ- 
ent weaves used. The breaker fabric with its peculiar 
construction permits the strength and the resistance to 
motion necessary to maintain the tread upon the 
closely^ woven body-fabric. The thinner, smaller 
weaves, in lapping the bead, play a most important 
part in the quality of the ultimate product ; but, in them- 
selves, they are relatively simple, both in grade of 
cotton fiber and method of weave. 

The tire designer must select his cotton, for the cot- 
ton fiber or staple varies greatly in length. The diam- 
eter of one fiber is so small that if you were to lay two 
thousand of them side by side, they would measure 
only one inch. Tiny and fragile as they are, 
these fibers, when properly chosen with respect to 
length and twisted together, become, like other com- 
munities, strong in numbers. In a thirty by three and 
one half inch cord tire there are over 1700 miles of fiber 
if placed end to end; but in a cord tire thirty-five by 
five there are more than 5700 miles. The builder's 
choice of fibers of the proper length gives strength 
and service to the tire fabric. Yet, as is the case with 
men in the army, it is not necessarily the largest 
ones that we depend upon for the most work. Fibers 
vary in length up to one and three quarters inches. 

How important a part is played by organization ! In 
the case of the tire, the fibers are organized by cotton- 
mill operations into fabric and then built up by the 



134 THE EEIGN OF RUBBEE 

rubber maker into a tire, to the end that each ply, each 
thread, and each fiber work in unison. The manu- 
facturer who is able so to control his millions of little 
staples that they will act as one is the Marshal Foch 
of tire service. When tires are run under-inflated or 
overloaded, the harmony of this organization is dis- 
turbed by a sort of mass attack on one sector, which 
throws too much strain on the inside plies. As a con- 
sequence, breaking begins. 

In tread design a cue is taken from Mother Nature, 
who grows tough skin on the bottom of a dog's foot 
and furthermore cushions it by pads of soft flesh. 
The tread of the tire is the wearing surface, a tough 
composition; but under it is a yielding foundation, 
soft, flexible, and snappy. 

The black tread has been evolved after a painstak- 
ing, intricate study, and the chemists have worked 
long and diligently in their laboratories to produce 
such a highly resilient rubber mixture. When tested 
on machines built for the purpose against the abrasive 
action of carborundum, these treads outwear dry 
leather by about two and one half times ; with both ma- 
terials wet, they outwear leather more than ten times. 
An interesting test was run some years ago to compare 
sheet-iron and several rubber compositions. This black 
rubber mixture resisted the action of a powerful sand 
blast three times as long as iron. The black rubber 
tread composition, therefore, on a pneumatic tire is 
the material most resistant to road abrasion that the 
chemist in his laboratory has been able to produce. 

A tire is not a tire until it has air in it. The inner 
tube has one purpose — to hold air. Although there 



THE PNEUMATIC AUTOMOBILE TIEE 135 

have been various attempts to substitute other things 
than air (and far be it from me to condemn research 
in this direction), thus far no substance with which to 
support the tire has been found equal to air. It is 
the most easily obtained; it is the most springy sub- 
stance known; and its only weakness is the ease with 
which it escapes through a very small hole. Despite 
the study of puncture-proofing and the substitution 
of oth«r substances, none of them has met with suffi- 
cient popular service to call it important to the tire 
industry. 

The tube, made of a very extensible rubber mixture, 
is the simplest part of a tire. Stretch a piece of an 
old one. Notice how the part next to the tread has 
deteriorated from the heat, and yet the part next to 
the rim is still strong. In designing tube thicknesses 
and sizes, tire designers try to choose the correct thick- 
ness, length, and diameter to permit the tube to run 
many miles beyond the distance that the casing will 
run. A trick here lies in the design, in the compound- 
ing, and in the type of vulcanization, which gives to the 
tube such resistance to heat that it does not become 
weakened or assume a permanently large size, a condi- 
tion making it impossible to put the tube back into 
another casing after the original one has been used up. 

The flap of the straight-side tire is a little article 
that is often overlooked. It is a piece of formed 
fabric and rubber used only in straight-side tires, for 
the purpose of preventing this soft rubber tube from 
forcing itself down underneath the bead. Many of the 
troubles of motorists are due to the flap, which, dur- 
ing the hasty application of the tire, flap, and tube 



136 THE EEIGN OF EUBBER 

upon the rim, is displaced, folded, or broken. The 
result is that, instead of protecting the tube, the flap 
becomes a means by which the tube is pinched and 
quickly broken through. 

The one great aim of the tire designer is to build a 
perfectly balanced product, so made that its parts 
work in unison. After all, one of two things happens 
to give an end to a tire ; either the tread wears through 
or the fabric breaks under repeated bending. There 
are, however, occasions when the tread wears unduly 
before the fabric has really run its life, and where the 
fabric breaks before the tread has been used up. The 
constant aim of the tire designer is to attain this per- 
fect balance ; to build his tire like the ' ' one-hoss shay. ' ' 

The earlier designs of pneumatic tires followed the 
principles then known for bicycle tires. Indeed, much 
parallel invention was under way in the early nine- 
ties. 

The histories of bicycle and of automobile tires are 
closely interwoven. Fundamental principles were 
pretty generally worked out for the bicycle before the 
coming of the automobile. Eeally, Daimler's first 
machine was a sort of motor-cycle. Being a little 
skeptical of the pneumatic, these first motor-car 
builders experimented with many varieties of solid and 
cushion tires; but as none of them was satisfactory, 
they turned to the pneumatic, adopting the single- 
tube bicycle tire. Although the single-tube tire was 
fairly satisfactory, it would not stand up under the 
heavier and faster cars. The tires were then made 
much heavier and larger than they are to-day; some 
manufacturers found that to keep pace with the in- 



THE PNEUMATIC AUTOMOBILE TIRE 137 

creasing size, weight, and speed of the automobile, it 
became necessary to produce a tire built to withstand 
vastly greater stresses. Farwell, in his ''Story of the 
Tire'' (1912), says: ''The makers now [about 1900] 
turned back to the original Dunlop clincher detachable 
tires as more suited to their needs and began to develop 
a distinct type of automobile tire. The wired-on or 
Dunlop tire, which was developed into the straight-side 
tire dT the present day, was enlarged and strengthened 
and put upon the market by its makers, the Hartford 
Rubber Company. At about the same time the B. F. 
Goodrich Company brought out their Goodrich 
clincher, which was the first American tire of this type 
to be made for automobile service. 

"In 'November, 1900, at the first exclusive Auto- 
mobile Show held in the ^ Gardens ' there were 33 auto- 
mobile makers and eight tire exhibitors, nearly all 
showing single tube pneumatic and solid tires. Dur- 
ing the next two years most of the manufacturers 
dropped the single-tube and were making double de- 
tachable tires only." The automobile shows of then 
and now appear strikingly different. 

We must not pass over these early names without 
giving credit to Michelin et Cie., the earliest French 
rubber manufacturers, who had the honor of first ap- 
plying the pneumatic tire to the automobile. Because 
the first broad use of the automobile was in France, 
and the manufacturers there felt the necessity for pro- 
tecting the mechanism of the car from road shocks, 
this development came about. 

Hard to apply and still harder to replace, these old 
tires were clumsy things as a rule. They were difficult 



138 THE REIGN OF RUBBER 

to inflate with any means at hand in those days. 
They gave relatively little service, and were hard to 
change. 

The history of the cord tire has been somewhat ob- 
scured. John F. Palmer patented it for bicycles in 
America in 1892. He took his patents to England, 
where the new tires were so much faster in bicycle 
racing that the officials handicapped the riders who 
used them. It was a gift of free advertising which 
led to the prompt adoption by all riders and the ex- 
tended use of the "Palmer Tyre" made by Mr. C. H. 
Gray at the India Rubber Works, Silvertown, near 
London. 

Mr. Thomas Sloper, however, in 1891 had conceived 
the cord idea and filed a provisional specification in 
the British Patent Office. Manufacturers would not 
listen to him when he sought their interest with his 
germ of a great idea. So the final specification was 
not filed, and the aggressive Palmer captured the Eng- 
lish market. 

Palmer adapted his principle to the automobile tire 
in 1895 but his web tire failed. His all-warp fabric 
with fine weft threads, however, was the forerunner 
and basis of the thread fabric today contained in 
essentially all cord tires. Sloper was employed by Mr. 
C. H. Gray, who foresaw the value of the idea for auto- 
mobiles and developed a successful cord tire, called the 
Palmer Tyre, which was later taken to America and 
made by the Diamond Rubber Co. and the B. F. Good- 
rich Co., with many improvements, as the Silvertown 
Cord Tire. 

How ideas travel 1 The cord idea began in America, 



THE PNEUMATIC AUTOMOBILE TIRE 139 

went to England a bicycle tird, and returned grown- 
up into the automobile tire. 

But the English tire contained two plies of heavy 
cord, like rope. To attain simplicity of manufacture, 
Americans took the lead again. The Morgan and 
Wright Co. (U. S. Tire Co.) and the Goodyear Tire and 
Rubber Co. almost simultaneously came forth with 
tires made of woven thread fabric. It was not a suc- 
cess «it first. When the tires came to be inflated upon 
a bag during cure, and the methods improved, the 
nearly perfect cord tires as we know them were the 
result. 

Let us take a trip into the factory and see how a 
tire is made. The compound for the tread, which has 
been mixed in the mill-room, is delivered into another 
room ; the beads are formed in still a different part of 
the factory ; and the side walls, which have been rolled 
out on the sheeting calenders, go into still a different 
room : it is a huge plant in all, turning out thirty-thou- 
sand tires every day, fifteen miles of them rolling out 
evefry twenty-four hours. The tire factory is, to say 
the least, a lively place. 

A visitor finds a seeming confusion of men, machin- 
ery, fabric, and rubber, with tires the outcome. It is 
not easy to picture the making of a tire, for each part 
is made in a different part of the plant and assembled 
at the building machine. Cord fabric is f rictioned and 
coated with a resilient compound on the three-roll cal- 
enders of the calender room. Here the steel wipes or 
frictions rubber around the threads. All cotton in a 
tire mill is called fabric. 

Since the threads of the fabric run at an angle 



140 THE REIGN OF EUBBER 

of about forty-five degrees to the circumference of the 
tire, the fabric must be cut on the bias. And so large, 
heavy rolls of this rubberized fabric are conveyed 
by the truck system into the bias cutting room, where 
they are carried through rapidly operating bias cutters 
that shear off certain widths. Operators roll them 
up, keeping plain fabric, known as 'Miners," between 
them, so that the adjacent layers of unvulcanized rub- 
ber may not stick to itself and make the building of 
the tire impossible. These bias blocks are then con- 
veyed to a table where workmen overlap the edges, 
using the proper width for the different sizes and dif- 
ferent plies. After being thus spliced, they are rolled 
up into bundles, each separated by liners, in the 
proper length to make a given number of tires of a 
certain size. The same cutting to width and length 
of the breaker fabric is done in different places, 
as is the cutting of the side-wall sheet rubber. 

The tread rubber is carried to the tread-forming 
room, where the rubber is softened on a warming-up 
mill and squirted through the die of a tubing machine, 
coming out of this die at a definite thickness and width 
for each different size of tire. In some factories these 
treads are formed on a calender, and in some by a 
tubing machine ; but, in any event, the exact width and 
thickness at each point is controlled by measurement. 
The operations are conducted by skilled men, to make 
certain that the exact weight, necessary not only for 
economy but for quality, is gained. 

Meanwhile, by an operation that would take a chap- 
ter in itself to describe fully, the bead is prepared. If 
it is a rubber bead, it has been formed on a tubing ma- 



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'!~^. ' ' --^ '"■ __^-- 




il„'fifji^W 


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^iflH^^^H^^ 


t,^^^ 

















Courtesy of The Fisk Rubber Co. 

PLACING THE UNVULCANIZED TIRE IN THE MOLD 



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i 


B| 


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■'***^^^^^^^'*^^' ' bI 


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Courtesy of The Fisk Rubber Co. 

FILLING THE VULCANIZERS WITH THE MOLDS 



THE PNEUMATIC AUTOMOBILE TIRE 141 

chine and pressed in a hot mold to a defined size, with 
a layer of fabric around it. 

At the building machine, one sees the operators fit 
in the proper place a metal core. This core is de- 
signed to be of the size that is correct for the inside 
of the tire, depending upon the process by which it is 
to be made. If it is a fabric tire, which is finally to 
be finished in a mold, this core is of exactly the size ; 
if it m a cord tire, however, the core is a little smaller, 
for the mold operation in making a cord tire consists 
of stretching it, while being vulcanized, upon an air- 
or water-bag. According to the construction of the 
tire, the plies of canvas are wound on this core by a 
machine in the order in which they have been laid up 
by those who spliced the bias strips together. The 
operator places the end of the canvas roll carefully 
upon the core, and sets the machine in motion. The 
tackiness of the rubber makes it stick to the metal ; and 
the fabric is stretched at exactly the necessary tension 
as it is wound on the core. Meanwhile, rollers are 
pressed by weights or springs upon the fabric in order 
to join the plies to each other firmly. Half the fabric 
previously having been put on the machine, the earlier 
formed bead is applied on top of it, in the right posi- 
tion and very accurately adjusted. Then in the build- 
ing the bead is wrapped about by the body plies. Af- 
ter the necessary plies have thus been built up, and the 
previously formed combination of tread, breaker-fab- 
ric, and cushion have been laid on and rolled down 
under pressure, the tire is taken to what is known as 
a finishing stand. Here the side walls are applied 
and the tire inspected. 



142 THE EEIGN OF EUBBER 

To gain accuracy and speed, much nice inventive 
work has been done in the making of tire-building ma- 
chinery. Machine-built tires are more precise and 
uniform than those built by hand. Before the tire 
is modeled to its approximate shape and ready for the 
final step of molding, there are a number of operations 
to be performed by these machines. If it be a fabric 
tire, the operators who work on the finishing stand lift 
it to a rack on a truck. If it be a cord tire, on the other 
hand, it is sent to a stripping table, where the core is 
removed, the tire is dusted on the inside, and an air-bag 
or a water-bag of heavy, thick rubber, which has been 
previously painted with soapstone solution to prevent 
it from curing to the fabric, is inserted. 

If it be a fabric tire, it then must go down to the vul- 
canizing room, where there are long rows of heaters. 
The tire is trucked to these heaters ; and a mold, in two 
halves, is brought by a powerful conveyor, in front 
of the workmen, who lift the tire and its core 
and place it in the lower half of this mold. The 
mold has been designed so that it is of exactly the 
exterior shape that the tire is to have when finished, 
including all the lettering and other features. As the 
tire travels along a metal belt, the top half of the 
mold comes down from an automatic conveyor that has 
carried it out of the way above the operators, and is 
carefully guided into place on the tire. The mold 
gaps open, for the tire in this form does not fit it ex- 
actly. In the mold are the protuberances that form 
the depressions in the tread design and hold the tire 
away from the mold until pressure forces it into place. 

Carried away on the automatic conveyor, the tire, 



THE PNEUMATIC AUTOMOBILE TIEE 143 

together with, many others, is loaded into the shell of 
the vulcanizer, in the bottom of which is a plate or 
platen, which, before the mold was filled, rested in a 
position nearly at the top of the heater. This platen 
is fixed upon a plunger moved by water pressure in a 
cylinder below. The lowering is done by simply push- 
ing the molds down a short inclined plane upon the 
platen, until there has been made a stack of twenty to 
twenty-five molds in the heater. After this, the cover 
is placed on this open vulcanizer; by a simple device 
it is locked in place so that no steam can escape. The 
molds are then forced together by hydraulic pressure 
and the soft rubber takes the form of the mold, after 
which process steam is applied and the vulcanization is 
begun. 

Great accuracy has been gained in recent years from 
the use of automatic, temperature-controlling instru- 
ments by which an operator has to turn but one valve 
to maintain an exact temperature during the desired 
time. At the end of the time, it automatically turns 
the heat off and gives a signal by which the operators 
know that the vulcanizer is ready to be discharged. 
In the discharge the hydraulic ram raises the molds 
to a height where the men can pull them by a rope and 
a winch upon the traveling conveyor, along which they 
are carried. The two halves of each mold are separ- 
ated, the tire removed, and the mold again filled. 
These are to the production man beautiful operations 
that give rapidity and accuracy to the vulcanization of 
tires. 

In the case of a cord tire, a somewhat different proc- 
ess is used; for, as stated, an air- or water-bag is 



144 THE REIGN OF EUBBER 

placed in the tire. The tire is then put in the lower 
half of the mold ; the upper half is lowered on it. Air 
or water connections are made to proper pipes. When 
the tire is in the vulcanizer, hot water is forced into 
the water-bag in order to stretch the tire and drive it 
by internal pressure against the mold. The object 
desired in cord tire vulcanizing, is so to design and 
mold tires that the fabric will not be displaced. 

After vulcanization, the casing is lifted from the 
mold, removed from the core or water-bag, and 
sent to the inspection room, where it is coated on the 
inside with mica paint to prevent the inner tube from 
sticking to it. Then it is wrapped for distribution. 

The manufacture of inner tubes is very simple when 
compared with the manufacture of the tire case. The 
tube, with the exception of the reinforcement around 
the valve, is made of one composition, sheeted on a 
sheeting calender to the proper thickness to make a 
tube of a given size. This sheeted rubber is then trans- 
ferred from the central calender room to the tube de- 
partment, having been previously cut to a width de- 
sired for each size. Then it is unrolled and separated 
from the liner upon a zinc-topped table, where it is cut 
to a definite length, corresponding to the length of the 
tube for each particular size. Carefully, it is rolled 
upon a former or mandrel, which is simply an iron 
pipe carefully polished and of the correct diameter 
to give the inside size of the tube. In some factories 
the tube is formed on a tubing machine, in which case 
it is extruded from the die of the machine, round in 
section. Then it is cut to the length required; after 
which process it is carefully stretched upon the man- 




LOAD, INFLATED WITH 6o POUNDS PER 
SQUARE INCH AIR PRESSURE 



NORMAL LOAD OF 8 50 POUNDS, INFLATED WITH 
60 POUNDS PER SQUARE INCH AIR PRESSURE 




OVERLOADED 41%, NAMELY TO A TOTAL OF 

1200 POUNDS, INFLATED WITH 60 POUNDS PER 

SQUARE INCH AIR PRESSURE 



EFFECT WHEN OVERLOADED TIRE INFLATED 

WITH 60 POUNDS PER SQUARE INCH AIR 

PRESSURE IS RUN OVER A STONE 



THE PNEUMATIC AUTOMOBILE TIRE 145 

drel. Once, however, upon the mandrel, whether 
sheeted or extruded, it is wrapped with fabric. 

After this operation, it is stacked on trucks, the 
units being separated by iron plates at the end; and 
the truck-load of mandrels with their rubber tubes 
upon them are pushed into long horizontal vulcanizers, 
the doors closed, and steam turned in. Sometimes the 
valve-pad reinforcement, which is a combination of 
rubber and fabric cut to an oval shape, is applied be- 
fore vulcanizing ; at others it is applied after vulcaniz- 
ing. At the end of the time of vulcanization, the tubes 
are stripped from the mandrel by the simple process 
of blowing air between the tube and the mandrel. 
Taken to another room the tubes have, by a skilfully 
used bit of apparatus, the two ends buffed, cemented, 
and vulcanized together. From here, the tubes are 
sent to a table where the valve stem is applied, if it 
has not been applied, as in some plants, before the 
splicing operation. They are then inspected in water 
for leaks, and packed for shipment. 

How should we take care of a tiref The principle 
developed in the field of engineering of only loading 
a beam to within a reasonable factor of safety applies 
here. If you build a house, you make certain that the 
beams underneath your floor are large enough to carry 
many times the greatest load that you ever expect to 
assemble upon that floor. Look at the picture of a 
tire section under no load, normal load, and overload. 
The inside of the tire has become flattened with over- 
load or under-inflation, conditions really affecting the 
tire in the same way; and the inside layers or plies, 
slightly shorter than the outside layers from bead to 



146 THE REIGN OF RUBBER 

bead, then carry too great a proportion of the load. 
As a result, when that tire is driven over a stone, it 
is liable to take a shape that seriously distorts it. 
And, too, because of greater internal friction, the 
amount of heat is increased. Hence, the fabric weak- 
ens, the rubber deteriorates rapidly, and the little 
fibers one by one begin to break ; until some day, when 
least expected, one of the plies will break through 
Then, instead of a six- or eight-ply tire, there will be 
only five or six. As in the case of a rope with one 
strand broken, the load becomes excessive for the other 
strands; and some time thereafter they will break 
down with the usual blow-out. A tire is really a sus- 
pension-bridge, the cords being fixed at the two beads 
and shaped by air pressure.. The air is not much com- 
pressed during service, but it is required in order to 
maintain the cords under the necessary tension and to 
permit them to work in the most natural way. 

Of the total power of the motor in an automobile, 
part is absorbed in the mechanism of the car and the 
remainder, estimated to be more than 80 per cent., is 
transmitted to the rear tires to be expended in push- 
ing the machine against the wind, up hill, and against 
other resistances. Driving over bricks and bumps, 
dodging around automobiles at the side of the road, 
our tires are subjected to power as well as dead load 
and to sudden changes in strain; These jerks, bumps, 
and cuts by rough stones on the road's edge, that let 
water into the fabric, are the killing forces that de- 
stroy tires. If tires were treated as most of our prop- 
erty is, we should carefully examine them month by 



THE PNEUMATIC AUTOMOBILE TIRE 147 

montli. The older ones should be shifted from the 
position of greatest work, namely, the rear, to the 
front; for we should think of them as old faithful 
horses gradually to be retired to easier jobs, while the 
younger ones are called upon to carry the heaviest 
burdens. 

How much work does a tire do I If one thirty-two 
by four inch tire on the rear wheel of a car carrying 
a load^ of fifteen hundred pounds runs ten thousand 
miles up a 4.4 per cent, grade, the work it has to do, 
engineers tell us, is 2026 horse-power hours. This is 
equivalent to lifting more than four billion pounds of 
stone up one foot. The computation, to be sure, as- 
sumes the tire to be on the up-grade all the way; but 
if it goes up-grade only one quarter of the time, the 
work done would lift the Washington Monument about 
twelve feet. When your tire goes one hundred miles, 
it does as much work as you would do if you shoveled 
220 tons of coal into your second-story window. Dur- 
ing such a job you would perspire pretty freely; the 
tire heats, too. We have learned by experiment that 
when this four-inch tire was run for an hour at twenty 
miles per hour, the temperature of the tire just under 
the tread had increased 371/2 degrees; at forty miles 
an hour, the increase was 75 degrees. In the hot days 
with the thermometer ninety-five degrees in the shade, 
and 110 degrees on the road surface, imagine the tire 
heated to 180 degrees, or nearly enough to boil water. 
Is it any wonder that the rubber wears rapidly then? 
These figures of temperature show that the motorist 
has considerable to fear if he rides at excessive speed 



148 THE REIGN OF EUBBER 

in hot weather, or if he permits his air inflation to be 
reduced to the point where there is maximum flexing 
and consequently increased rise in temperature. Re- 
gardless of that, rubber tires resist just such wear to 
a greater degree than any other known structure. 

Motoring is not wholly a matter of engines and 
chassis. *' Bone-shaker" vehicles are gone forever. 
To the pneumatic tire may be given credit for the as- 
tounding growth of the automobile, for it has per- 
mitted both speed and comfort. 



CHAPTER X 
TRANSPORTATION BY TRUCK 

Trajisportation is a mighty word. Indeed, civili- 
zation measures its scope and development by its effi- 
ciency in moving men and materials. The change from 
the days when each household was self-sustaining and 
all life was agricultural is a history of transportation. 
The Neanderthal man killed his meat in the forest and 
carried it to his cave. He lived from day to day. The 
barter principle of trade was given up only as trans- 
portation made possible the movement of commodities 
from distant fields of origin to centers of use. Banks, 
warehouses, and exchange systems depend upon move- 
ments of goods over the world ^s highways. 

After human effort came the ox-team, after that the 
horse-drawn wagon, then the railroad, and finally the 
improved highway for motor transportation. In fact, 
if one looks over the world as it is now, he finds each 
of these ancient and modern methods of movement 
realized in different parts of it. The measure of the 
intelligence of peoples, in any event the standard by 
which they are rated in the family of nations, is pretty 
largely that of the efficiency of their transportation 
systems. The famines in China illustrate how vital 
highways are in modern life ; for there were provinces 
filled with starving people, and but a few short miles 

149 



150 THE REIGN OF RUBBER 

away, as we in the United States measure distance, 
there was plenty of food; yet the lack of highways 
made it impossible to move the food to those who 
needed it most. 

Our great railways are main lines of travel, requiring 
secondary lines with fast and prompt service to feed 
them with the products of the soil and industry. For 
this purpose the motor-truck, developed during the 
last two decades, constitutes at once the most spectacu- 
lar and efiicient means. The tourist does not enjoy 
the crowded thoroughfare; his horn too often fails to 
stir the truck driver ahead to yield half of the pave- 
ment. Yet the very freight the truck carries means the 
prosperity that makes touring possible. 

The motor-truck takes its value from certain charac- 
teristics that may be termed fundamental. It can move 
goods at relatively high speed; its power is sufficient 
to permit its carrying loads of any size to meet the de- 
mands of industrial and commercial enterprise. It is 
adaptable, more so than any other known vehicle, to 
various service requirements. The milk-truck in early 
dawn rushes its supply from the farm dairies to the 
centers from which babies are fed; dirt from excava- 
tions for sky-scrapers is hauled away in dump-trucks ; 
the department-store delivers its merchandise for miles 
into the country. Through the efficiency of the truck, 
regularity of service is habitual, although still the con- 
dition of roads affects seriously the movement and 
life of the vehicles. There is, to be sure, some differ- 
ence of opinion among students of motor transporta- 
tion as to how far the range of trucking may be con- 
sidered efficient. The railroad, however, is the main 



TRANSPORTATION BY TRUCK 151 

line and the motor-truck the feeder, or the rapid means 
of communication between adjacent industries or cities. 
Motor transportation is economical, for the cost per 
ton mile has been reduced to a point making the ex- 
tension and use of trucks possible. Probably the 
truck wiU never be able to compete with the railroad 
on long hauls. 

Recent years have witnessed a striking change and 
development in the use of the truck, for it has come 
to be a serious competitor of the trolley-car. Both the 
bus and the street-car have their definite places ; each 
has its advantages. I would not wish to say that 
either will displace the other. The motor omnibus 
systems in New York, London, and Paris as well 
enough known to support a conception that they would 
not be conducted upon so extended a scale were not the 
cost of transportation low and the profits unmistak- 
able. Freedom of movement; ability to follow the 
lines of growth of the community and so give service 
where the laying of tracks for trolley-cars would be 
highly expensive ; avoiding obstacles, as in the case of 
parades, fires, or temporary obstructions — this funda- 
mental principle of flexibility, without doubt, renders 
the motor-bus a means of passenger transportation 
that has come to stay and that will develop in the fu- 
ture. Recently some busses have been run on rails, 
but they are still in an experimental form. There is 
no one of these different types of motor-trucks, busses, 
or cars in which rubber or the rubber tire in one form 
or another is not an essential. Indeed, a feature of 
the latest addition to this family is the cushion driving 
wheel of the rail car, in which, underneath the usual 



152 THE EEIGN OF EUBBER 

steel wheel and protected from the weather by side 
flanges, is a special rubber cushion to give comfort to 
the rider. The rubber tire, therefore, is a commodity 
without which it is doubtful if any of these transpor- 
tation schemes would serve. 

From the time when Sir Isaac Newton, in 1680, sug- 
gested the steam-driven wagon, down through the 
years, attempts have been made to revolutionize trans- 
portation by self-propelled vehicles. The early disap- 
pointments and failures of the steam wagon in its 
various forms were due to the lack of a soft cushion to 
smooth out road inequalities and to reduce vibration. 
Probably for this reason more than any other, these 
early rapid-transit enthusiasts came to the invention 
of the solid road-bed and the smooth rails that we as- 
sociate with the railroad. The first plan to avoid 
shocks was to cushion the wheels with tires of solid 
rubber. The idea of air in a tire was a later develop- 
ment. The electric vehicle pioneered by Colonel A. L. 
Riker in 1898 was one of the earliest truck develop- 
ments, although the steam truck was more fully worked 
out in England and the gasolene internal combustion 
engine was developed in France and America. One 
still sees on the English streets steam-driven trucks. 
For all of these heavy services the solid motor tire, 
which was a natural offshoot of the solid carriage tire, 
has proved to be the most logical medium by which 
cushioning, long life, and efficiency can be gained. The 
solid tire differs from the pneumatic tire, which is so 
vital to passenger-car transportation, in being rubber 
all the way through. 

The inventor of the original solid rubber tire is un- 



TRANSPOETATION BY TRUCK 153 

known. The history of tires in England seems to give 
credit to Thomas Hancock who, in his book written in 
1856, suggests solid rubber tires to relieve vibration. 
They were, however, manufactured before 1856, for 
the records show the firm of Charles Mackintosh & 
Co., to have manufactured such tires for vehicles as 
early as 1846. Hancock says: ''These tires are 
about an inch and a half wide and one and a quarter 
thick. * Wheels shod with them make no noise and they 
greatly relieve concussion of pavements and rough 
roads; they have lately been patronized by Her 
Majesty.^' But because of their sticky qualities and 
the property of softening readily with heat, these early 
tires gave a relatively short service. There is a 
patent on record in England, granted to Thomas Smith 
in 1845, the principle of which was spokes set within a 
felloe of metal in a trough-like form, the open part be- 
ing outward and containing a tire. No mention, how- 
ever, is made of rubber in connection with this patent. 
During 1856, in England, M. Coles Fuller brought out 
a combination solid tire composed of cloth, canvas, or 
other fibrous materials. 

The first introduction of solid tires for cabs in Lon- 
don was in 1861, but difficulties were experienced in 
attaching the rubber to the wheels. In 1863 N. H. 
Carmont took out a patent for holding the metal part 
of the tires on the felloe with a dovetailed section to 
receive the rubber tires, which were grooved to fit the 
channel. Later, another company, known as the Noise- 
less Tyre Co., was formed to furnish tires for the 
Shrewsbury Cab Co., the first firm to introduce the use 
of solid rubber tires in England. Upon the invention 



154 THE REIGN OF RUBBER 

of the bicycle in England in 1867, it was found neces- 
sary to relieve the vibrations of the old *' bone- 
shaker"; and solid rubber tires were manufactured 
that were cemented into a groove in the rim of the 
machine. These tires were followed in 1879 by cushion 
tires, which, although no larger in diameter, possessed 
increased resiliency produced by a small hole running 
through the center. They wfire specially devised for 
what was then known as the "safety" machine, which 
followed the old high bicycle. 

The introduction of the motor-bus in England ne- 
cessitated a further departure with regard to rubber 
tires. Not only were pneumatic tires out of the ques- 
tion, but it was found impossible to retain solid rub- 
ber in the rim when the weight of some six or seven 
tons was imposed upon it. Therefore, it was necessary 
to vulcanize some sort of a retaining band in the bed 
of the rubber. Now, it is a very difficult matter to 
unite thoroughly a non-yielding body like steel with an 
elastic body of the nature of rubber. In time, this 
has been etfected. So metal rings of various sections 
were used for this purpose, and detachable rims en- 
abled these ring sections to be fitted on the felloe of 
the wheel. But the Scotland Yard authorities pro- 
hibited the use of sectional tires for use on public 
vehicles in England; and this action, to some ex- 
tent, checked the development of this class of tire. 

The Shrewsbury & Talbot tire, the trade name of the 
Carmont tire, was introduced into New York. It at 
once gained approval, and it remained until later de- 
velopment drove it from the market. It is interesting 
how the point of view of the public has changed in the 



TRANSPORTATION BY TRUCK 155 

last fifty years, for the early solid tire offered the 
public in 1856 by the Boston Belting Co., was received 
with the unfailing skepticism then ready for anything 
in the nature of an innovation. Because rubber wheels 
made no noise, they were considered detrimental to 
the safety of pedestrians ; and the inventors were de- 
terred from taking out patents by the authorities, who 
warned the manufacturers that vehicles equipped with 
such tires were a menace to public safety. We even 
find the rubber sole and the rubber heel catalogued 
under the name of ''sneakers," even though the safety 
and comfort of the user, as well as economy, are in- 
creased by their use. 

The most practical development of the solid tire for 
carriage purposes was one invented by Arthur W. 
Grant, later known as the Kelly-Springfield tire, 
which probably more than any other one invention led 
to the popularity of rubber on horse-drawn vehicles. 
The rubber was held in place on the wheel by means 
of longitudinal wires running through the tire and 
forming circles of smaller circumference than the rim 
flanges.' Built of long-lived rubber mixtures, this tire 
was capable of positive attachment in the channel or 
rim. A little later the tire was modified by the so- 
called "side-wire" carriage tire, invented by James 
A, iSwinehart of Akron, in which the wires were passed 
outside the rubber body. 

The automobile has so completely dominated the 
field that the horse-drawn vehicle has become only a 
means of wagon transportation, and the internal wire 
or any other type of carriage tire has essentially dis- 
appeared. We need not, therefore, describe the nu- 



156 THE EEIGN OF EUBBER 

merous other methods of holding a piece of solid vul- 
canized rubber on a wheel for carriage purposes. 

After years of development and trial, the solid truck 
tire of to-day has come down to us in one form : a steel 
base upon which is a layer of hard rubber, and, upon 
that, the mass of soft rubber giving comfort, cushion- 
ing, and resistance to wear. The function of the mo- 
tor-truck tire is to provide traction for the wheels, 
and, as a protection to the mechanism of the truck and 
load upon it, to cushion them. The first idea of the 
metal-base tire came from Europe — a steel band 
grooved in the form of dovetails. Into these grooves 
was forced a layer of rubber mixture that would be- 
come hard rubber on vulcanization. This served as a 
stiff base impossible to remove from the steel, although 
chemically not united with it. Before vulcanization 
of the hard rubber, a layer of a resilient tread com- 
position was applied, and the whole vulcanized in a 
mold under pressure, so as to form the shape desired. 
Thus was developed the wireless tire introduced into 
the market in 1909. To-day the steel-base tire is uni- 
versally used on motor-trucks and is called the truck 
tire. 

The steel base on which this solid truck tire is built 
is a continuous band of channel-steel, the lower surface 
of which is smooth and the surface between the flanges 
machined with a series of circumferential slots that in 
cross-section have the appearance of dovetailed de- 
pressions. Because accuracy of measurement is im- 
portant, that they fit the wheels, the manufacture of 
these bases is a specialized process in steel mills. 
They must also be made to fit exactly into the metal 



TEANSPORTATION BY TRUCK 157 

molds after the tire is on them, during the vulcaniza- 
tion process. In the course of manufacture, the sur- 
face of the steel is roughened* by numerous corruga- 
tions. In some factories fine, sharp, flint-sand is 
blown against the base with a powerful air-blast; in 
o-thers, it is copperplated ; in others, it is treated with 
acid to pit the surface with an infinite number of fine 
depressions. The purpose of this work is to give a 
surface to which the hard rubber mixture may hold in 
innumerable little points of attachment, these points 
making the security of the hard rubber base certain. 

In the operation of manufacture in the rubber mill, 
after the metal base is thus cleaned, in order to fill 
these little depressions -with a hard rubber composi- 
tion, it is coated with cement. After drying, this base 
or permanent band is mounted upon a horizontal shaft 
placed in front of a special calender. The hard rub- 
ber compound containing an amount of sulphur ap- 
proximating 32 per cent, by weight of the crude rub- 
ber has previously been mixed in the mixing room. 
The numerous other ingredients are chiefly those ma- 
terials that serve to vulcanize it simultaneously with 
the wearing part. This hard rubber compound is 
softened and passed through the rolls of the calender, 
which form a sheet of unvulcanized hard rubber mix- 
ture, the precise width of that part of the base be- 
tween the flanges. When the proper amount adheres 
to this steel band, the base, with its layer of unvul- 
canized hard rubber, is taken to another calender, 
where a continuous sheet of a soft rubber mixture is 
run, until the right thickness, depending upon the size 
of the tire, i-s rolled up upon it. At this point, the cal- 



158 THE EEIGN OF EUBBER 

endering operation is stopped, and the tire is removed 
from the support of the wheel. Rectangular in section, 
it then is taken to the trimming machine, where the 
excess of soft rubber is removed. By this process the 
shape in section of the tire is made as nearly as pos- 
sible to conform to the shape desired after vulcani- 
zation. 

The soft or wearing rubber may be applied to the 
hard rubber base by another process. First it is 
softened upon a warming-up mill. After softening 
it the workmen feed it into the -opening in a heavy 
tubing machine, where it is forced by great pressure 
through a die. From the die the rubber issues as a 
long, solid mass. The die is the shape in section that 
the finished tire is expected to be. Different sized 
tires — four-inch, five-inch, six-inch, seven-inch, etc., — 
require dies corresponding approximately to the size 
desired. The mass of rubber is forced through this die 
until a strip a little longer than the circumfer- 
ence of the tire has been passed out of the machine. It 
is then cut off and laid away to cool. Finally, when 
ready for building up on the hard rubber base that has 
been run on the calender, this mass of soft rubber is 
roughened on the surface where it will be in contact 
with the hard rubber. After being carefully cemented 
with a rubber cement and dried, it is placed in what is 
known as "an up-setting machine capable of handling 
accurately and easily as much as 150 to 300 pounds. 
This long mass of rubber is there applied carefully to 
the hard rubber; and after preliminary pressing and 
the fitting together of the two ends, it is in the ap- 
proximate form in which it will issue from the mold. 



TRANSPORTATION BY TRUCK 159 

By either of these two processes, the calendering proc- 
ess or tubing-machine process, we have a steel base 
with a hard rubber layer upon it, and upon that the 
mass of soft rubber of the size and form of the final 
truck tire. 

This tire is then taken to the vulcanizing or curing 
room, ready for the final operation of vulcanizing. 
The vulcanizing process is similar in principle to that 
used "Xvith a pneumatic tire ; that is, the doughnuts, 
with their tires in them, are placed upon a movable 
plate or platen held at the top of a hollow, cylindrical 
shell known as the "heater" or * ' vulcanizer. " By 
mechanical devices the molds are pushed on top of the 
plate, the plate is lowered by letting cut a little water 
through the hydraulic mechanism, and another mold 
is placed on top of the first. The tires then are 
pressed by hydraulic pressure into the exact shape 
and conformation of the inside of the moulds. "When 
the steam is turned into the vulcanizer around the 
molds, the vulcanizing operation begins. 

There is probably no part of rubber operation that 
requires greater care in manufacture than this one of 
vulcanizing or curing a solid tire. Not only are we 
dealing here with rubber that is to be vulcanized, but 
with a thick mass of rubber. The thermal conductivity 
of rubber is very low; in other words, it is a very 
good heat-insulating material. Furthermore, various 
compounds are different in their resistance to the pas- 
sage of heat through them. It requires from one to 
two hours to bring the temperature of the center of 
an ordinary-sized solid tire up to that of vulcanization. 
For this reason, solid-tire curing temperatures have 



160 THE REIGN OF RUBBER 

usually been kept relatively low and the time of vul- 
canization relatively long. 

After the vulcanization is completed, cold water in 
some plants is run into the heater and allowed to re- 
main long enough to cool the mass of metal and rubber. 
The control of steam has been maintained by auto^ 
matic temperature-controlling apparatus, the ma- 
terials have been carefully examined, and every pos- 
sible precaution necessary to insure uniformity of one 
of the most delicate products made has been taken — a 
product that is submitted to tremendous variations in 
service. After the tire comes from the mould, it is in- 
spected, the little extra amount of rubber that has 
flowed out of the mold and which is known as rind, or 
overflow, is cut off, and the tire is ready for sale. 

The solid tire of the permanent-band type is then 
ready to be applied to the wheel, and much of its serv- 
ice depends upon proper application. To apply the 
tire, the wheel is removed from the truck and laid upon 
a heavy press operated by hydraulic power. The tire, 
which fits the felloe band of the wheel tightly, is placed 
in position; then the two plates are brought together, 
the action forcing the band or base of the tire upon the 
wheel. The process usually requires a pressure of 
twenty tons — ^in any event, far more pressure than any 
tire will ever be subjected to in service. 

There have been several types of demountable tires 
made which are capable of application in a garage or 
on the road; but they are gradually disappearing be- 
cause they work loose. Since the tire itself is so heavy, 
one or two men can scarcely apply it while the wheel is 
still on the truck. Therefore, the permanent band- 




Photo by Underwood & Underwood 

A FREIGHT TRUCK 





Courtesy of The White Motor Co. 

ONE OF THE TRACKLESS TROLLEYS 



TEANSPORTATION BY TEUCK 161 

pressed-on type has come to be the most largely used 
truck tire. 

We see some wheels equipped with two tires in the 
rear; these tires or "duals" have a wide use because 
two tires radiate the heat -more readily than one. 
Since there is not so heavy a mass of rubber to ab- 
sorb the heat, there is consequently not so much dif- 
ficulty of radiation. And there seems to be a somewhat 
greater gasolene efficiency from the truck when there 
is a relatively small amount of rubber in actual con- 
tact with the road. Skidding, too, is reduced by the 
dual tire ; and since the units are relatively small, it is 
possible for a fleet of trucks to carry the same size of 
tires in front and in rear, using them singly on the 
front wheels and in pairs on the rear ones. The large 
single tire, however, has its field; and it would be 
scarcely wise to say that any one type of tire, single, 
dual, or any other, has an unlimited field of usefulness. 

The solid tire is -probably subject to more abuse 
than any other rubber article, loaded as it often is to 
double the amount the tests have proved advisable. 
Run at speeds by which a high degree of heat is gen- 
erated, the mass of rubber being unable to radiate its 
heat so easily as a pneumatic tire, truck tires have 
been known to absorb heat until the temperature in- 
side them has become so great that the rubber decom- 
posed with a generation of gases, and the tires blew 
out. In all the data that have been gained about 
blow-outs it is a safe statement that they rarely occur 
except when the overload of the truck is so high that 
it is beyond the ability of tires to stand it. This 
raises one of the vital questions for the truck user; 



162 THE REIGN OF EUBBER 

namely, the relation of size of tire to the load he ex- 
pects to carry. Despite all arguments to the contrary, 
it is economy for him in the long run, whether he uses 
one make of tire or another, to put on his truck that 
tire proportioned in size to the loads that he wishes 
to carry, to the speed the truck will stand or the law 
allows, and to the road conditions. By so doing, he 
will gain a service before the tire is broken down that 
will make additional cost for the larger tire an econ- 
omy rather than an expense. 

Non-skid devices on solid tires, such as chains, cause 
some trouble, and there is a certain amount of confu- 
sion among users about them. While on the pneumatic 
tire the chain is capable of movement, on the solid tire 
there usually is but one place where it sets itself 
against the rubber. Proved from the days of the in- 
ternal wire, it is true that wherever rubber comes in 
contact with an inflexible body, such as metal, it will 
wear out rapidly. Thus the chain wears out the solid 
tire at its points of contact. This has led the manu- 
facturers to develop non-skid tires, which have served 
to hinder slipping upon wet pavement, snow, or ice. 
There is still a great field, however, for improvement 
in devices which will resist the slipping tendency and 
yet in no way injure the product. 

Many trucks are equipped with large pneumatic cord 
tires, some of them as much as nine inches in sec- 
tional diameter. These extra large ones have found 
their way into extended practical use, although the six- 
inch, seven-inch, and eight-inch tires are the usual 
sizes. The fundamental advantages resulting from 
the use of pneumatic tires on trucks are cushioning and 



TEANSPORTATION BY TRUCK 163 

traction greater than can be obtained from the solid 
tire. The cushioning ability of a pneumatic tire, 
when not inflated too highly, is about four times that 
of a solid tire of the same carrying capacity. As a 
result, the operation of the truck is faster, with con- 
sequent economy of operation; there is less injury 
to a fragile load, for the riding is easier; but there is 
grave danger from blow-outs and punctures. Gen- 
erally^ pneumatic tires have been used only on the 
smaller trucks, namely, those up to three tons in carry- 
ing capacity; for the four and five-ton trucks the 
solid tire still leads. 

Technical men still discuss the practicability of pneu- 
matic tires ,on trucks. There are delays caused by the 
changing of tires even when demountable rims are 
used. Since the rim and the tire are heavy, and the 
rim is generally rusted on, the time required to make 
a change is often a serious matter. Furthermore, the 
air pressure carried, from ninety pounds in a six- 
inch size up to 130 pounds in the nine-inch size, is 
much higher than for the smaller tires. Most garages 
are not equipped with pumps capable of maintaining 
these higher pressures. And, too, the center of grav- 
ity of the trucks is raised, for the pneumatic tire is 
higher than the solid tire. This has led to a few ac- 
cidents when blow-outs have occurred and trucks have 
toppled over on the road. As a rule though, such dif- 
ficulties have not been numerous; and the pneumatic 
tire on trucks is probably here to stay. Such beauti- 
ful products are these big pneumatic tires that it is 
always a pity when a puncture does occur, to see them 
ruined before the truck can be stopped. 



164 THE EEIGN OF EUBBER . 

Although some wonderful long-distance hauling from 
the rubber metropolis, Akron, to Boston and to San 
Francisco has been done on trucks equipped with pneu- 
matic tires, experience differs. Many seem to believe 
that the pneumatic tire spares the trucks numerous 
jars and strains ; and, therefore, the truck itself can be 
made lighter. But, and this is important, if the truck 
be spared jars, it is because of the air-cushion. Be- 
cause these cord tires contain eight to sixteen plies 
of cord fabric, they are stiff. To attain long life for 
them enough air pressure must be used to avoid too 
much flexing with consequent cord breaking. The 
compressibility and elasticity of air enables the tire 
to absorb jars; therefore, when air pressure is high, 
the tire is hard — ^indeed, more so than a solid tire. 
Then the purpose is defeated. Highway engineers 
realize that when the pneumatic tire is inflated as it 
should be, the pressure to the square inch of road con- 
tact is the same regardless of the load carried, and is 
based entirely on the necessary inflation pressure. If 
in obtaining wider area of contact the inflation pres- 
sure is reduced, the tire will become unduly flattened — 
a condition which will lead to rapid deterioration. To 
balance low air pressure for softness against high 
pressure for mileage is not possible in large pneu- 
matic tires. 

The solid tire, being made completely of rubber, 
bulges out under load, because it cannot be compressed, 
but it is sufliciently plastic to flow. If you place a pen- 
cil with the soft eraser upright on the desk and push 
it downward, the eraser will bulge at the sides ; it is not 
compressed but is displaced. A rubber tire oozes out 



•TRANSPORTATION BY TRUCK 165 

in the same way; and as it spreads on the pavement, 
this so-called traction wave flows around continually 
through various sections of the tire and causes in- 
ternal action. The designers, however, have so ar- 
ranged the shape of the tire that even if it does flow, 
only internal heat results, which, if the tire is used 
properly with respect to the load carried, does not be- 
come sufficiently excessive to have a serious effect upon 
its lif-e. Since there is no danger from punctures, 
cuts, and so on, the average mileage of the solid tire 
is greater than that of the pneumatic tire. 

Of recent years, a new idea has been expressed in 
the building of tires that combine the softness of the 
pneumatic under low inflation and the length of life 
of the solid. Resilient solid tires capable of service 
under heavy trucks will solve the truck tire problem; 
for these permit speed, ease of riding, freedom from 
changes on the road, and longer mileage than is pos- 
sible from the large pneumatic. This type is the 
truck tire of the future. 

In truck transportation heavy loads are demanded. 
Can the roads stand the pressure? A road is, after 
all, nothing more or less than a hard layer of material, 
brick, concrete, macadam, upon native soil. If this 
layer is made thick enough, heavy loads may be car- 
ried over it without danger of breaking through. But 
when, as has been the case in too many instances, the 
highway engineers have simply floated a thin layer of 
brick and concrete upon clay without drainage to re- 
move water, the trucks have actually broken through. 
Increased speed of a vehicle tremendously increases 
the impact that its wheels make on the roadway where 



166 THE EEIGN OF EUBBER • 

there is any unevenness. However, the answer to the 
maintenance of roads probably lies less in a limita- 
tion either of the type of tire or of the width of contact 
with the road than in road construction. Eoads should 
be heavy enough to carry the future motor transport. 

Since motor transportation on highways is here to 
stay, would it not be wise to build roads of a width 
to carry two streams of traffic with safety; of a con- 
struction sufficiently deep to carry increased tonnages 
at low cost per ton-mile; with a drainage system to 
carry off the water? Roads should permit perma- 
nence and flexibility to the development of motor 
transportation. Even as they are, streams of trucks 
carry goods and people over hundreds of routes. 

Statistics may be dry, but they stimulate the imag- 
ination. In the economics of truck use, railroad men 
recognize the advantage of the motor-truck in short 
branch-line operation, trap-car service, suburban dis- 
tribution, terminal distribution, and the utilization of 
outlying yards in lieu of yards in congested districts. 
In the handling of food supplies from farm to city the 
radius has been extended by about fifty miles, a matter 
of vital moment for milk and other perishables, which 
serves to save time for the farmer and to reduce thfe 
cost of living. Education is affected. Consolidated 
schools in country communities, with the improve- 
ments thereby obvious, have been made possible 
through the speed and safety of the motor-bus for the 
transportation of children. This use is rapidly grow- 
ing. 

The extent to which motor-truck haulage has pro- 
gressed is well set forth in a census by the United 



- TRANSPORTATION BY TRUCK 167 

States Bureau of Public Roads for the eastbound traffic 
only on the Boston Post Road at the New York-Con- 
necticut line in October, 1921, which shows nearly every 
type of commodity and many million tons being 
carried. For such transportation the total number of 
public express lines is probably about one thousand, 
says the National Automobile Chamber of Commerce ; 
and a Senate committee has estimated the annual 
motof-truck tonnage hauled in the United States over 
the highways at 1,438,000,000 tons. In the motor-bus 
field 108 cities were using motor-bus lines at the begin- 
ning of 1922. 

But truck tires contribute to the esthetic as well as 
the economic welfare of a nation. In England, the 
char-a-banc is changing the life of its people. No 
longer are the delightful, picturesque little places in- 
accessible. The railroad is never a good tourist route. 
The highways, hedge-lined, are beautiful. A trip 
from London between the rows of brilliant rhododen- 
drons down to Salisbury, the winding road along 
Runnymede, leaves memories never to be forgotten. 
Where the automobile has shown these beauties of 
England to hundreds, the char-a banc carries thou- 
sands. The English people are discovering England, 
and they axe doing it on truck tires. 



CHAPTER XI 
WATER-PROOF FOOTWEAR AND CLOTHINa 

Men, like cats, abhor wet feet. No substance, how- 
ever, was successfully made into a water-proof shoe 
until rubber came to be used for that purpose. The 
South American Indians were the pioneer rubber shoe 
makers of the world. Pouring the latex from trees on 
their feet, they permitted it to dry; it became an un- 
vulcanized, water-proof ''rubber,^' as we should call 
it, or a ''galosh" as it would be called in England, 
exactly fitted to the foot. Since it was doubtless un- 
comfortable to hold feet over a flame to dry the milk, 
the Indians made clay lasts or forms of the shape and 
size of the foot, each constructing his own. Over 
these they poured latex, to be evaporated in the smoke 
of a palm-nut fire. 

The first rubber shoes worn in this country came 
from South America in 1820 — a pair of very elaborate, 
gilded rubbers, which a Boston sea-captain brought 
home as a curiosity. The first serious importation 
for selling purposes was made five years later. At 
that time, Salem, Massachusetts, one of the most ag- 
gressive business centers, exported to South America 
maple lasts, to which the natives took very kindly. 
Dipped shoes, about equally thick in all parts, were 
the only kind that proved serviceable up to the time 

168 



FOOTWEAR AND CLOTHING 169 

of Goodyear ^s discovery of vulcanization. In shape, 
the first American shoes were simply overshoes. 

The first lot of these Amazon India rubber shoes 
made of pure gum was sold in Boston in 1825 by 
Thomas Wales. These were made to fit a shoe of 
any size : there were no rights or lefts ; they stretched 
over the leather shoes. 

The first domestic vulcanized rubber shoe was made 
by Goodyear in 1840. The L. Candee Shoe Factory 
at Hampden, Connecticut, was organized in 1845, un- 
der licenses of the Goodyear patent. Then came the 
Goodyear India Rubber Manufacturing Co. at Nauga- 
tuck. The demand became so great that by 1860 there 
were 1,200,000 pairs of rubber shoes made in this 
country. 

In the late fifties a new overshoe came into vogue, 
which, with various modifications, was the arctic, in- 
vented and patented by T. C. Wales. It consisted 
of a shoe with a layer of rubber between a cloth out- 
side and a cloth lining. 

The rubber boot is an American product, there be- 
ing no record that any rubber boot was imported from 
South American countries. Nathaniel Hayward in- 
troduced the hard heel in the forties; and from that 
day to this the rubber boot has been a popular article. 

The lumbermen's shoe is an outgrowth of the old 
women's buskin made in the fifties — a laced shoe 
lined with Canton flannel and made to wear directly 
over the stocking. 

George Watkinson, then president of the old Col- 
chester Rubber Co., wrote: *'In 1860 there were only 
eight companies making rubber shoes in this country. 



170 THE EEIGN OF EUBBER 

They took precedence as follows : Hayward, Ford (or 
Meyer), New Brunswick, Newark, Candee, Naugatuck, 
Boston Eubber Shoe Company, Providence (or Na- 
tional). We had three styles of boots, the 'Hip,' the 
'Knee' or 'Cavalry' and the 'Short.' Shoes were 
simply 'overs,' 'buskins,' 'three-strap sandals,' 'one- 
strap sandals,' and 'Jessie sandals.' The arctic was 
just come into use at the Naugatuck Company under 
the Wales patent, which was however not sustained, 
and every one went into the making of arctics. ' ' 

Thus has developed over the years one of the most 
intricate phases of the entire rubber industry; for if 
one looks to-day into the catalogues of the many large 
institutions that make rubber boots and shoes, he finds 
them classed something like this : There are "boots," 
viz., as we know them, boots that come to the knee or 
to the hip, loved by the small boy in the spring ; there 
are the "miners," a water-proof boot particularly 
employed because of the heavy work on ore or stone 
that it must resist; there are the "dull shoes," the 
"lumbermen's," usually a leather or a woolen top 
shoe coming nearly to the knee, with only the bottom 
part around the foot made of rubber; there are the 
"artics" and the "gaiters"; and finally there is that 
miscellaneous group classified as "light goods." 

In order to give some idea of the extent of these 
styles and sizes, the catalogues have been analyzed 
of four leading rubber manufacturers, viz., the B. F. 
Goodrich Co. at Akron, Ohio ; the Mishawaka Woolen 
Co. at Mishawaka, Indiana; the Hood Eubber Co. at 
Watertown, Massachusetts; and the United States 
Eubber Co. in several different factories. The analy- 



FOOTWEAR AND CLOTHING 171 

sis shows that the styles and sizes made by these four 
companies when added together give a table that is 
astonishing in its intricacy : 



Classification 


Number of Styles 


Boots 


7,953 


Miners 


850 


Dull Shoes 


4,616 


Lumbermen 


6,027 


Arctics 


7,953 


Gaiters 


8,358 


Light Goods 


41,930 


Total 


77,687 



Thus there are 77,687 varieties of shoes and boots 
of all kinds made by four companies alone. Each of 
these styles and sizes is here computed as a pair, and 
consequently the number of individual shoes, each dif- 
ferent, reaches the astonishing total 155,374. These 
figures give some idea of the tremendous intricacy 
involved ; the problem of manufacturing, warehousing, 
inventory, etc., is so vast that out of the total rubber 
industry in all its phases it is probable that the boot 
and shoe end of it is the most complicated. Figures 
for 1919 show there were 9,208,000 pairs of rubber 
boots made, and 66,195,000 pairs of rubber shoes and 
overshoes, or a total of 75,403,000 pairs. These had a 
value of $90,780,000. 

Light shoes, as we call them in the rubber industry, 
are generally known as rubbers; they are the light- 
weight rubber overshoe that we put on to protect 
water-absorbing leather shoes on a rainy day. When 



172 THE EEIGN OF EUBBER 

buying rubbers, a customer of the older generation 
usually had laid before him by the clerk a pair pulled 
out of a drawer containing a heterogeneous assort- 
ment, each two tied together with red string. A rub- 
ber shoe was stretched over the leather shoe; there 
was no question of fit. 

As this clumsy, ill-fitting shoe, formerly known as 
the ''gum shoe," often peddled about the country in 
market baskets, has been replaced by its stylish mod- 
ern successor, wrapped in tissue-paper and packed in 
a neatly labeled carton reposing on the shelf of the 
dealer with all the dignity of a leather shoe, there has 
come a significant change in the rubber shoe industry. 
Now it is necessary to use craftsmanship; and the 
rubber shoe last designer, who determines styles, 
is an important factor. While he is little heard of, 
he affects the appearance of the feet of the nation 
about as Paris affects the appearance of women's 
dresses. Since styles of leather shoes are so numer- 
ous, the rubber designer must gather his ideas from 
the leather shoe trade, attending the style shows, de- 
termining what the leather shoe changes are going to 
be, and adapting his rubber shoe accordingly. He 
tries to fit as many different styles of leather shoes 
as possible. 

The first step the designer takes is planning the 
last. A last is nothing but a wooden form, some- 
times an aluminum one, of the size and shape for the 
particular style and size that is to be made. There 
are the high heels of the Louis type, the medium or 
Cuban heel, the low heel, the long vamp, the short 
vamp, the high instep, and the low instep. After he 



FOOTWEAR AND CLOTHING 173 

has grouped all these styles together, he selects those 
which possess the most points in common. The shoe 
of each group most closely typical of the lot is then 
worked up in wood into a composite model last. This 
last is one upon which a leather shoe would not be 
made ; it is larger, for the rubber shoe must fit over 
the leather shoe. Then begins the work of an artist. 
The designer must trace the outline of the bottom to 
get what he knows as the bottom pattern, and then 
he must work up each step in the rubber, taking care 
of two points: the style and the effect of wrinkling 
and bending, in order that all parts of the shoe work 
together in action. When the last is finally designed 
and tested so that the shoe made from it is found to 
fit exactly, and the style is right in the best judg- 
ment both of the last designer and the manufacturer 
of shoes, the manufacture begins. 

The manufacture of light shoes employs the funda- 
mental principles by which heavy boots, arctics, 
gaiters, and other types are made ; for these all differ 
only in detail. Shoes are made of rubber mixtures and 
cotton fabric, or rubber mixtures and woolen fabric, 
since warmth in winter is important, particularly in 
the arctics which have become so popular. In its 
essentials, the rubber shoe industry consists of a proc- 
ess by which the rubber mixture, sheeted to the proper 
thickness, assembled with fabric, and cut into the 
proper form, is laid by skilled workmen piece by piece 
upon the last, so that in its unvulcanized condition 
there is formed a perfect rubber shoe with all the mark- 
ings, the corrugations of the sole, the band around the 
top, that make up the finished shoe. In a rubber shoe 



174 THE EEIGN OF EUBBER 

factory, one is impressed by its intricacy ; there seem 
to be many different hand operations. Each of these, 
however, is essential; and all parts come together in 
the making-room from different preparation rooms. 

The rubber compounder who makes up the formulas 
for the different compositions has, after years of ex- 
perience in this oldest of the divisions of the rubber 
industry, found that certain mixtures give maximum 
service. Since appearance plays a large part, he has 
found himself limited. Rubber shoes, as a whole, con- 
tain only small percentages of sulphur, to avoid bloom. 

In the plant, the operations start with a soling cal- 
ender. The compound, which contains rubber and the 
various strengthening and coloring pigments, will 
have been mixed in the mill room in the way in which 
all rubber mixtures are made. It is then taken to 
the calender room, where it is warmed on the warming 
mill and fed into a four-roll, small-sized, rubber shoe 
calender. The idea of the four-roll calender is to per- 
mit the use of an embossing roll, for the three-roll 
calendars used in larger articles deliver the sheet of 
rubber smooth on each side. Big rolls are housed in 
heavy framework; and naturally, were they to be 
removed at any time, it would be a long, difficult 
operation. Therefore these soling calenders have 
been made small in size, capable of delivering a long 
sheet of composition in width a little greater than the 
maximum length of the sole for any large-sized rub- 
ber shoe. Different styles for different purposes re- 
quire slightly different markings on the bottom. If 
you will examine your shoe, you will find the grade 
numbers, the name of the maker, and little variations 



FOOTWEAR AND CLOTHING 175 

in the corrugations, indicating different styles and 
shapes. Upon the fourth roll has been cut by an arti- 
san the depressions which will produce these raised 
conformations on the sole, and the rubber is embossed 
by this roller as the sheet passes between it and the 
adjacent one. To permit different types of impres- 
sions, there are usually several of these embossed rolls. 
By means of easy locking devices, and since it is small, 
the enJDOSsing roll may be removed readily and an- 
other one substituted. 

The sole is one of the fundamental parts sheeted 
on the calender to the required thickness. As it runs 
out in a long strip, workmen cut it up in sheets of the 
proper length and put it in "books," which consist 
of boards with sheets of cloth attached on one side 
to prevent the layers of rubber from sticking together. 
In another, but slightly larger calender, may be run- 
ning at the same time the thin sheet of the ''upper" 
compound. This thin sheet will have marked upon it 
by the embossing roll the outline of the upper, the out- 
side part of the shoe that goes around the foot above 
the sole. In still another calender may be running si- 
multaneously cloth, wool, or cotton of the particular 
weave needed, upon which is being laid friction, the 
soft rubber composition forced into the interstices of 
the threads. The fabric may also be coated. Here we 
have the sole, the upper, and the fabric parts. I have 
not mentioned the various other small but important 
parts that go to make up the shoe: the little trim- 
mings, the reinforcing parts or stays, the insole, the 
heel, all of which are made in different rooms, for va- 
rious purposes. Since there are many parts and many 



176 THE EEIGN OF EUBBEB 

sizes of each shoe, there must be many workmen and 
many machines. 

Only the three fundamentals — sole, fabric, and up- 
per — are here considered. These pass from the calen- 
der room to the various preparation rooms where 
skilled workmen, or in some cases machines, cut out 
these several parts into the particular shape required. 
Finally, these numerous compositions and shapes are 
assembled in the making-room in accordance with a 
''ticket" or plan previously made. A given number 
of shoes a day requires a large number of parts. The 
making of the ticket in the shoe factory is an important 
operation of management. This ticket must show at 
each step in the operation the proper quantity or num- 
ber of each part for each type of shoe, so that hour 
by hour and day by day the parts will come to the 
making-room in the necessary amounts, with no delay 
to the shoemakers. In one of these large, well-lighted 
making-rooms, you will find lasts in number and sizes 
specified by the ticket. 

The shoemaker's one duty is to lay upon the last 
in the proper order these different parts. Since the 
insole is next to the foot, or leather shoe, as the case 
may be, while the fabric that is to serve as the 
strengthener lies at the bottom between the insole and 
the outsole, the first operation is that of laying the in- 
sole upon the bottom of the last. Outside of that is 
placed the fabric lining and reinforcing pieces. Then 
the upper is applied and rolled down, so that it exactly 
and tightly fits the last. There it is stuck definitely to 
the other parts and set to the height and points of 
shape that the designer has intended. Finally the out- 




Soft Ffubbe 
Hard /fu£?ber 
3 tee/ 3<7se 



Courtesy of The B. F. Goodrich Co. 

m PARTS OF A SOLID TIRE 




Courtesy of The B. F. Goodrich Co. 

A lady's slipper, made in the modern rubber factory 





■p 


H 


l^^s^^l 


^^^^H 






1- ■ . ■ 

h 
* 


Js'Sfl 


'''l^^^^^l 


■as- 






■ 


n 




^^^^f 





Courtesy of The B. F. Goodrich Company 

a rubber shoe made on the AMAZON 



FOOTWEAR AND CLOTHING 177 

sole is laid on and rolled down, usually a layer of 
cement having been put upon it that it may stick 
tightly to its adjacent rubber. The outsole is care- 
fully forced by a roller in the hands of this skilled 
operator around the edge and over the upper, the 
operation makings neat outside binding. Each type 
of shoe is constructed a little differently, and yet here 
lies the crux of the whole thing : the bringing together 
of these different-shaped rubber pieces upon a pre- 
viously designed last, with the shoe thereby formed 
definitely to the shape intended. 

After they have been formed upon lasts, these 
light-weight rubbers are put upon trucks and pushed 
out of the making-room into another room where sev- 
eral at a time are dipped into a bath of a special var- 
nish, the purpose of which is to give the rubber shoe 
the high polish that is so desirable. Any grade of 
varnish would not accomplish the desired purpose; 
for it might come out of the vulcanizer with a motley 
colored sheen or dull. Years of experience have de- 
veloped this varnish to withstand heat and the action 
of sulphur without change of color. 

After they are varnished, the shoes, still on their 
lasts, are returned to the racks on the big truck and 
are pushed through another room into the vulcanizer. 
This vulcanizer is, in reality, a large room containing 
steam coils that serve to heat the air in the room, the 
hot air in turn supplying the heat to the rubbers and 
so vulcanizing them. Thus the rubber shoe is vulcan- 
ized in what we call dry heat, that is, in hot air, by a 
carefully regulated temperature over a period of sev- 
eral hours. When this time is completed, the trucks 



178 THE REIGN OF RUBBER 

are pushed down into the inspection room. Here the 
shoes are removed from the lasts, inspected, and 
sorted ; the excess of fabric and rubber around the top 
of the shoe is carefully cut off by skilled trimmers; 
and the rubbers are packed into boxes ready for ship- 
ment to the shoe store. 

If we were to follow through the manufacture of 
heavy boots, lumbermen's or arctics, we should dis- 
cover essentially the same principles, though carried 
out on a heavier and larger scale. Where in the light 
shoe, for instance, there is around the rubber upper 
only one ply of fabric, in the heavy boots there are 
two plies near the top, graduated to as many as seven 
plies near the bottom, with reinforcing layers of rub- 
ber. And while the sole of a light rubber may contain 
two plies of fabric and be only a matter of five thirty- 
seconds of an inch thick, the sole of a heavy boot usu- 
ally is strengthened by a thick, tough insole and sev- 
eral other plies of fabric, being often half an inch 
thick. 

Furthermore, in the vulcanization of different types 
of boots, there are several methods; for one of the 
fundamentals in vulcanizing such heavy articles is to 
create enough pressure to avoid the development of 
air bubbles and blisters. Therefore, different proc- 
esses are used to give a pressure sufficient to hold 
the layers against the last tightly enough so that blis- 
ters will not be created. In the boot, design or bal- 
ance of parts plays an even greater role in service 
than is the case with ordinary rubbers, for it is sub- 
jected to excessive wear. 

Why are some shoes white, some red, and some 



FOOTWEAR AND CLOTHING 179 

black? There is a good reason for the majority of 
them being black; it is the history of the industry. 
We are willing to have black, because black is so con- 
sistent a color of leather shoes and is so natural a 
one to our eyes. We seem not to care for variegated 
colors upon our feet. However, the manufacturer's 
one aim has been to find those things which give serv- 
ice, regardless of what they might be, where they 
might -come from, or what they might look like. He 
makes a definite study of special types of service. In 
the use of boots, he must consider the cold weather of 
the North and the hot climate of the South. He must 
consider the fisherman who shovels herring, fills bas- 
kets with cod, or stands in the canning factories of 
the Pacific Coast day by day in slime and oil. Here 
a boot must withstand a particular condition and give 
a long wear. He must also consider the miner who, 
in the copper-mines, works in acid water containing 
copper salts; he must remember the lumberman snag- 
ging his foot-covering as he fells the giant trees in the 
forest ; a hole may mean a frozen f oot^ — perhaps death. 
All these varieties of service are studied in the little 
office of the designer of rubber boots and shoes. In 
the effort to develop service qualities under such diffi- 
cult conditions, there have come to be different colors 
in rubber shoes. The color itself, however, has been 
secondary. They could be, nearly any color of the 
spectrum wished by the consumer. 

On the tennis-court the players move quickly to and 
fro; the school children to play basket-ball crowd the 
gymnasiums; with sure feet, they jump and run on 
the airy, soft-soled tennis-shoes. Tennis-shoes con- 



180 THE EEIGN OF RUBBEE 

stitute a considerable part of the use of rubber as 
foot covering, for in 1919 there were 19,896,000 pairs 
of these canvas shoes with rubber soles. 

The fundamental principles of manufacture are es- 
sentially the same as with rubbers, except that in- 
stead of a rubber upper there is a canvas upper. 

Apparently Walter B. Manny, in 1891, first sug- 
gested the use of rubber heels. In the last ten 
years, and particularly during the last five years, the 
use of rubber heels on leather shoes has grown to 
astonishing proportions. They are resilient and soft 
enough to take away the effect of the blow of the foot 
as the heel strikes the pavement, removing therefore 
considerable jar from the body and giving comfort 
to the wearer. They are longer in life than leather. 
Therefore we find that an industry which was too small 
to be reported in the census of 1914 had grown in 1919 
to the extent of 138,468,769 pairs of rubber heels and 
a value of $14,238,000, a development which could not 
have taken place unless these heels possessed definite 
value to the wearer. 

What becomes of these rubber heels? The Census 
Bureau answers the question and propounds another 
when it says that the production of leather shoes in 
the year 1919 totaled 275,357,206 pairs. Thus, about 
half the leather shoes are equipped with rubber heels. 
Why? Because, while the shoemakers are in the 
leather business, when the wearers come to know the 
health and comfort to be derived from rubber heels, 
every one will demand and receive them on his 
leather shoes. 

The manufacture of rubber heels is typical of that 



FOOTWEAR AND CLOTHING 181 

of other molded rubber goods. The rubber mixture 
is sheeted out in about the thickness of the heel. Un- 
vulcanized blanks are stamped out of this sheet by 
dies in a power-driven punch press. The raw heels 
are inserted into molds, which consist of either two 
or three pieces, design plate, form plate, and cover. 
Molds have raised lettering or designs engraved in 
the plate. In place of the necessary holes for nails 
or screws, steel pins of corresponding shape are 
screwed in. Design and form plates are provided 
with guide-pins, so that the heel form fits with the 
lower plate. The thickness of the form plate corre- 
sponds with the thickness of the heel. Before the hot 
molds are filled, they are brushed with a solution of 
soap to prevent the rubber after vulcanization from 
adhering to the steel. 

The vulcanization of rubber heels is effected in 
hollow-plate presses like those used in the laboratory, 
except that they are larger. So that an equal pressure 
may be applied upon the molds, the platens must be 
parallel to each other. The presses are used in bat- 
teries of a dozen or more, the steam in each of which 
is automatically controlled. After the vulcanized 
heels are removed from the molds, the rind is trimmed 
off. The resulting rubber heel is to the human foot 
what the pneumatic tire is to the automobile. 

The modern rubber sole is an achievement of rub- 
ber compounding and manufacture. Nearly all the 
mixtures have in them a certain percentage of wool, 
cotton, or leather fiber mixed with the rubber and vul- 
canized. The compound is mixed in the usual way in 
the mixing mills, sheeted on the sheeting calenders 



182 THE EEIGN OF RUBBER 

to a correct degree of thickness, cut out to the approx- 
imate shape of the finished sole, and vulcanized in a 
sole mold of the usual character, for the necessary 
time and at the proper temperature, the mold being 
held together by hydraulic pressure. There are va- 
rious kinds of unusual types, such as soles with inserts 
of strands of stout cord under the ball of the foot and 
at the heel; there are special ones with knurlings or 
corrugations on the soles, although these are not 
widely used. 

No sooner had crude rubber come into the European 
markets than every practical man who worked upon it 
tried to make garments. The old English stage- 
coaches had outside top-seats; and since England is 
so rainy a country, it was natural for the men who 
traveled from Manchester to London, desiring to keep 
themselves dry and warm, to study how this new sub- 
stance could be used for the purpose. 

Many attempts were made in the years after 1790; 
but it remained for Charles Mackintosh of Manchester 
to find it possible to ''dissolve," as he called it, rub- 
ber in coal-tar naphtha, to apply it to cloth for water- 
proofing purposes, and out of the cloth to make a 
garment. This was the first practical rubberized gar- 
ment made; it was named from the inventor "Mackin- 
tosh," a word that has come into the English vocabu- 
lary. That great pioneer of the rubber industry, 
Thomas Hancock, became a business partner of Mack- 
intosh in 1833, and much of his study had to do with 
attempts to improve the rain-coat. Indeed, the first 
practical application of the Parkes method of cold 
vulcanization of rubber by the use of sulphur chloride 



FOOTWEAE AND CLOTHING 183 

in a solvent was the vulcanizing of the rubber which 
had been applied as a thin layer of composition upon 
the surface of these cloths. 

Emory Rider, who died May 24, 1884, worked with 
Goodyear in Springfield, Massachusetts. He is said to 
have been the first to vulcanize clothing, and he under- 
went extraordinary trials for want of suitable mechan- 
ical means for the vulcanization of large pieces of 
goodsr 

So important was the use of rain-coats considered 
during the World War that there was a total purchase 
of ponchos, rain-coats, and slickers by the Government 
amounting to ten million garments and costing more 
than forty-six million dollars. It is an industry to- 
day of infinite variety, largely, however, in respect 
to the styles of garments and the colors and weaves 
of cloth required. Man in his garments seems to wish 
variety, and women extensive variety, so that there 
are various hues, shades, weights, thicknesses, and 
weaves of rubberized garments. Generally speaking, 
manufacturers make them in three classes: there are 
single-texture fabrics, with one layer of fabric and a 
layer of rubber on the inside ; there are double-texture 
fabrics, with two layers of cloth stuck together by a 
layer of rubber between them; and there are fabrics 
with a layer of rubber on the outside. 

In the process of manufacture, after the choice of 
the proper composition, which depends considerably 
upon the quality and service which the particular coat 
is supposed to render, and upon the choice of the fab- 
ric, the rubberizing of the cloth, so far as single-tex- 
ture and double-texture cloth is concerned, is done by 



184 THE EBIGN OF EUBBER 

application to the cloth of rubber in the form of ce- 
ment. We still follow the original method in principle 
that was worked out a hundred years ago. A spread- 
ing-machine, as it is termed, is a simple apparatus 
looking like a long table, at one end of which is a roll ; 
above this roll is a metal sheet known as a knife or a 
doctor blade. This knife, by careful adjustment, is 
set down close to the fabric, which has laid upon it 
a certain amount of rubber cement that has been pre- 
viously 'prepared by churning the mixed composition 
in gasolene. As the cloth then passes between the 
roll and the knife, a thin layer of cement is laid upon 
the cloth. In its travels the cloth passes to the top of 
the long table, which really consists of a series of pipes 
or steam plates into which steam is forced; the heat 
generated thereby evaporates the solvent. Then the 
cloth is rolled up with fabric next to each concentric 
layer to prevent its sticking to the adjacent layer. 

The operation is repeated until the proper thick- 
ness of rubber is built upon the cloth, when it is, in 
the case of single-texture garments, passed on to the 
vulcanizing-room to be vulcanized. In the case of 
double-texture garments, the layer of cement is placed 
upon one side of each of two layers of fabric, and 
these two are then unrolled through a doubling-ma- 
chine, consisting of two metal rolls under high 
pressure, which force the two layers of fabric together 
rubber to rubber, so that they stick. As the cloth 
issues from the doubling-machine, it is rolled up and 
passed on to the vulcanizing room. 

With single-texture garments either one of two 
processes of vulcanization may be used. The original 



FOOTWEAR AND CLOTHING 185 

Parkes or sulphur chloride process is one of them. 
This is still much employed in Europe and more or 
less so in this country. In this process, the rubber 
side of the fabric by a continuous movement is car- 
ried in contact with a roller, the opposite side of which 
is turning half immersed in a weak solution of sulphur 
chloride in either benzine or carbon bisulphide. This 
gives a light, weak application of sulphur chloride to 
the rubber, so that on hanging festooned in a large 
room for a few hours, the rubber becomes vulcanized. 
In the case of the dry-heat method of cure, the fabric 
is festooned or hung across bars near the ceiling of 
a small room, the air in which is heated by steam 
coils on the bottom of the room. After a few hours 
the vulcanization is accomplished, and the fabric is 
removed, ready for subsequent operations. Double- 
texture fabric is usually dry-heat vulcanized. The 
rubber-surfaced fabric such as you see upon police- 
men and firemen for protection from water is some- 
times made by the application of rubber from a 
spreading-machine, but more usually, I believe, by the 
application of a thin layer of rubber in the usual man- 
ner on a friction and coating calender, after which 
it is dry-heat vulcanized in the way that has been de- 
scribed. The result, regardless of the process or pur- 
poses for which it is intended, is rolls of cloth with 
rubber on one side or between two layers. 

From such rubberized cloth, garments are made by 
manufacturing tailors by methods similar to those 
used by tailors everywhere. In building up the cloth 
into the garment, it is no longer sewed but is ce- 
mented together. After vulcanization of the cloth a 



186 THE EEIGN OF RUBBER 

second time in a dry-heat room, the seams adhere 
tightly enough to be effective in shedding water. 

Protection from the weather is, and doubtless ever 
will be, an extensive use for rubber in the service of 
mankind. The mother sends her child to school with 
rubbers and rain-coat. The business man wears his 
sandals ; the workman dresses in heavy garments and 
boots. Of vital value to health and comfort are rub- 
ber footwear and clothing. 



CHAPTER XII 
BROADENING THE FIELD OF SPORT 

Sport requires quickness of mind and muscle. From 
earliest times, the snappiest substance was chosen for 
sports of different kinds. Long before rubber was 
discovered, ball tossing was indulged in. More than 
four thousand years ago, in the twelfth Egyptian 
dynasty, the throwing and catching of balls was 
known; and we find that the early artists sculptured 
human figures engaged in this sport. A leather-cov- 
ered ball was used in the games on the Nile more than 
forty centuries ago, and one of these early specimens 
has a place in the British Museum. 

Using a leather-covered sphere stuffed with hair, 
the Greeks played ball. One can imagine that not 
many home runs were batted with such a dead ball. 
The Greeks believed in symbolism, for they played 
this ball-tossing game pripiarily in spring, to typify 
the emerging into life of nature after the ..gloom of 
winter. Later the princes of Europe played the game, 
as probably many others did, who could afford either 
to make or to purchase the balls. But South Ameri- 
can Indians had an advantage over the people of 
Europe, for the ball that they used was lively rubber ; 
the game therefore was more interesting. 

The American sport of base-ball, it is generally be- 
lieved, was founded by the Knickerbocker Club of New 

187 



188 THE REIGN OF EUBBER 

York in 1845. The earliest regulations, formulated in 
1858, specified that the ball should be composed of In- 
dia rubber and yarn, covered with leather. To-day the 
base-ball is built up around a rubber and cork core, 
weighing one ounce and properly vulcanized and 
molded in spherical form. Upon this is wound woolen 
yarn at a definite tension; the ball is covered with 
carefully tanned, selected, tough leather, sewed in the 
way that all Americans know. This combination of 
wool, rubber, and leather, which weighs between eight 
and eight and three-quarters ounces, is the thing the 
home run kings bat over the fence; it is what makes 
possible a game enjoyed by millions; it is the best- 
known article that contains rubber. 

But this it not the only respect wherein rubber 
serves the great American game. In the old days, the 
intrepid catcher caught the ball or it hit him ; but then 
the ball was pitched with less speed and fewer baffling 
curves than now. Later it became necessary for him 
to be armored with a body-protector made of rubber 
covered with fabric and blown up tight enough with 
air to absorb the shock should the ball strike it. There 
is many a catcher who has sent up a vote of thanks 
to rubber for protecting him against serious injury. 

Let us turn now to another great and popular game. 
Base-ball is played by comparatively few but seen by 
thousands. Golf is played by thousands and seen by 
few. It is estimated that there are in this country 
more than 500,000 golf players-, playing on about 2,500 
courses. In the year 1921 there were very close to 
7,200,000 golf -balls made and sold in this country. It 
has truly become a popular game. 



BROADENING THE FIELD OF SPORT 189 

There is considerable doubt just when and where 
the game of golf originated. Some authorities con- 
tend that the game is of Scotch origin; others say it 
began in Holland. Some believe the word ''golf" is 
derived from the Teutonic word Kolbe, meaning club, 
or from the Dutch word Kolf. One thing, however, we 
do know; the game was in some form played in Scot- 
land as early as 1353. 

The ^rst ball used was egg-shaped and made from 
beech wood; the club was carved from one piece of 
wood and shaped something like the present hockey 
club. The modern golfer, who loves the smooth green 
and the exactly spherical ball, to be sure of accuracy 
in putting, would indeed find himself lost in the at- 
tempt to putt an egg-shaped piece of wood with a 
hockey club. In those days there were no regular golf 
courses or any particular places of play. The players 
usually agreed on a starting-place and an objective. 
The contest was to determine which player could drive 
his ball to a certain object in the shortest time, and, in 
some contests, to arrive at a destination in the fewest 
number of strokes. 

Since all games change and progress, it was not long 
before the wooden ball was superseded by one which 
was made of hard-pressed feathers with a leather 
cover, and which was but a little larger than the pres- 
ent ball. So far as skill in its hand sewing was con- 
cerned, the cover was a work of art. It is stated that 
so many feathers were packed into one of these small 
balls that if released they would more than fill an or- 
dinary hat. Feather balls were used until 1848, when 
it was discovered that gutta-percha, a relative of rub- 



190 THE EEIGN OF RUBBER 

ber, could, under heat, be shaped in an iron mold to 
the form of a sphere. According to W. Dalrymple in 
''Golf Illustrated," of November 30, 1901, the real in- 
ventor of the ''gutty" golf -ball, was the Rev. Robert 
A. Paterson, for many years principal of the Bing- 
hamton Ladies' College in New York State. In 1845 
he rolled a lot of gutta-percha clippings into a ball, 
painted it, and used it on the links. One of the first 
Scotchmen to use this invention was William H. T. 
Peter. 

Naturally, many experiments were made with the 
new ball. The introduction of it tended to make the 
game more popular and somewhat cheaper. The ball 
had kinks of its own, as we d'uffers think all golf -balls 
have, one of which was a tendency to ' ' duck. ' * Gradu- 
ally it was found by the more persistent players that 
after a ball had been used a few times and been con- 
siderably bruised, the flight was better. Balls came 
to be made with marks on them, the scoring being done 
with a chisel or a hammer, and after a while with the 
mold itself. Although it took about six months 
properly to season a ''gutty" ball, when produced, it 
was quite serviceable and distinctly economical; for it 
could, when worn, be remolded. 

The game in the early days became so popular that 
an ordinance was introduced into the Scotch Parlia- 
ment in 1457 decreeing that "futball and "golfe" were 
not to be played at some certain periods that were 
set apart for training in archery. During the four 
hundred years following, the game remained almost 
entirely in its native land. Even in 1875 the royal 
and ancient game had made very little progress south 



BBOADENING THE FIELD OF SPORT 191 

of Scotland. But in 1890 it took sudden and popular 
hold, and since then it has developed with great ra- 
pidity. Comparatively new in the United States, the 
first amateur championship games were played over 
the old St. Andrews Golf Course at Yon-kers in 1894. 
The next year the first championship game was played 
under the auspices of the United Golf Club Associa- 
tion at the Newport Golf Club, Newport, Rhode Island. 

The solid gutta-percha golf -ball, with various forms 
of marking, held its own until 1898, when a new idea 
in golf-ball manufacture, and one destined to prevail, 
was introduced by a resident of Cleveland, Ohio, Co- 
burn Haskell. The story of this invention is of par- 
ticular interest to me, for this manuscript was written 
not a hundred yards from the site of the old building, 
now torn down, in which the first thread-construction 
ball was wound. One evening Coburn Haskell was 
discussing various inventions with B. G. Work, then 
superintendent of the B. F. Goodrich Co. at Akron. 
In the course of the conversation. Work remarked to 
Haskell : 

< ' Why don 't you invent something! " 

"What shall it be!" said he. 

**You ^re a great golf enthusiast," replied Work. 
''What we need for golf is a new type of golf -ball; 
more uniform and with a longer flight." 

Haskell lay awake most of the night dreaming of 
golf-balls. The next morning he remarked to Work, 
"Why not make it up of rubber thread wound under 
tension?" That appealed to the practical genius of 
Work as a clever idea and one that was the answer to 
the question. 



192 THE EEIGN OF RUBBER 

At that tii^e the B. F. Goodrich Co. was engaged in 
the manufacture of rubber thread for suspenders, and 
several skeins of it were brought up to Work's office. 
There Haskell set himself to the task of winding a 
golf-ball. Imagine a man unused to skilled work at- 
tempting to wind many yards of rubber thread under 
tension into a spherical form ! No sooner would the ball 
be partly wound than it would slip out of his fingers 
and fly away over the floor; then the work had to be 
done again. He gave it up at last, and some skilled 
girls were called in to wind the balls. The thread 
spheres were sent into the factory and covered with 
gutta-percha in a hollow mold. Haskell could scarcely 
wait for a train to Cleveland to try the ball on his golf 
course. He at once found it to be longer in drive and 
truer in putting. This original ball was composed of 
a gutta-percha core, upon which was wound thin rubber 
thread; the two substances were enclosed by a gutta- 
percha shell. 

The new Haskell golf -ball met with much prejudice. 
Not until 1901 was the first important test given to it 
in amateur championship contests at Atlantic City. 
There twenty out of the twenty-four starters in the 
qualifying round used the new ball, among them W. J. 
Travis and C. B. McDonald. Travis managed to win 
the qualifying medal with it, turning in a score of 157 
strokes and eventually winning the championship. 

This ball increased the length of the player's shot, 
but it was difficult of control. It ducked. The first 
balls made were put out with shallow lines on the sur- 
face. Dfeeper grooves were soon applied ; by them the 
difficulties with ducking were overcome. A short time 





^Kk^^^^^^^k^^^^^^^^^^P"" 't^ >''"!^^I^^^^^^^^^^^Hh 


W- ^T--- 


Ifp^i^' 



Courtesy of United States Rubber Co. 

THE SOLING CALENDER 




Courtesy of The B. F. Goodrich Co. 

AT THE MAKE-UP TABLE 




Courtesy of United States Rubber Co. 

SHOE VULCANIZING 



BEOADENING THE FIELD OF SPORT 193 

later the '^bramble" or "pebble" surface marking was [ 
adopted, with further improvement in trueness of 
flight. Through its snappiness the new ball brought 
with it the necessity for lengthening all courses. Hits 
that were laid out for the average players were made 
to look ridiculous. Irons came into use where drivers 
and brassies had formerly done the work. 

As time went on, longer and longer flights became 
possible from more and more scientific construction of 
the center and the cover of the golf -ball. Such rapid 
changes worried the officials of the golf associations 
who feared that the courses might be reduced to a 
mere drive and a putt. To curb the tendency to- 
ward excessive length of flight, for no man knows how 
far it might be possible to develop a golf -ball by means 
of the modem science of the rubber industry, the 
United States Golf Association and the Royal and 
Ancient Association of Great Britain joined together 
and agreed that the golf-ball must not exceed 1.62 
ounces in weight or measure less than 1.62 inches 
in diameter. The styles of marking were left matters 
of eiioice. 

The modern golf -ball is one of the most delicate, in- 
tricate, and scientific articles made by the rubber in- 
dustry to-day. It is composed essentially of three 
main parts. The center or core contains a heavy 
material such as lead, to give proper weight and thus 
influence the length of drive, and is usually mixed 
into a soft mixture. If you examined the photograph 
of a section of a golf -ball that has been frozen and 
sawed in two, you would see how large a part is 
occupied by this core. Many substances, steel, hard 



194 THE EEIGN OF RUBBER 

rubber, soft doughs, stiff pigments, even liquids, are J 
found in some of the many brands. Around it are ■ 
layers of rubber thread of several sizes, widths, and 
thicknesses. This rubber thread is made of the finest 
rubber and sulphur composition that the chemist can 
produce. Around the thread is then molded a gutta- 
percha cover. Not only must the cover be as resistant 
as possible to the edge of an iron, but it must be soft 
enough during the molding operation under heat to 
amalgamate with the outside layers of thread. The 
markings on the cover are carefully designed; for if 
they are too deep the ball will soar, if too shallow the 
flight will be low, if none at all the ball will duck. 
Balls of the same weight and size, the same core con- 
struction, and the same thread tension, molded in the 
same way, will show different distances by several 
yards when the indentations in the cover are of dif- 
ferent number, size, and depth. 

The painting operation of a golf -ball is one of those 
intricacies necessary to its proper construction. A 
good golf -ball paint is not one that can be bought from 
any paint-shop ; it must be chosen carefully. It is re- 
quired to adhere to the gutta-percha cover even when 
the ball is distorted or when it is struck with the edge 
of an iron. It must therefore be flexible and resistant 
to blows. It must not change color in the sun ; it must 
not crack ; and it must not be so soft that it will slow 
down the ball on a sand green by picking up sand. 

Perhaps one of the most important phases of its 
manufacture is the accuracy with which the core is 
made and the correctness with which the thread and 
other parts are applied, in order to make sure that the 



BEOADENING THE FIELD OF SPORT 195 

ball may be true to center. Only a truly spherical 
ball, with the center of gravity in the precise center, 
will give true flight and accuracy on the putting green. 

In the long course of manufacturing development 
that has produced the modern golf-ball, there have 
been many processes perfected. The original Haskell 
patent described '*a golf -ball comprising a core com- 
posed wholly or in part of rubber thread wound under 
high tgnsion and a gutta-percha enclosing shell for the 
core of such thickness as to give it the required rig- 
idity. ' ' This problem of winding thread under tension 
was no easy one. Therefore the invention of the wind- 
ing machine was one of the most important steps in the 
development of the golf-ball as we know it, and to- 
day these better-than-human machines work rapidly 
and accurately. 

The first stage in the manufacture of the golf -ball 
consists in the formation of the soft center. Upon 
this is wound a tape of vulcanized rubber. This core 
is then taken to the winding-machine; and upon it as 
a center there is wound the vulcanized rubber thread. 
A power-driven device does the winding. In the ma- 
chine the ball center is revolved upon a variable axis 
that moves enough and at regular intervals so that the 
thread, which is carried around by the machine and 
unwound from a shuttle, is wound in different great 
circles upon the core and evenly distributed over the 
entire body of the ball. As it passes from the spool 
the thread is stretched and wound upon the golf -ball 
under an exactly regulated tension. 

The flight of the golf-ball in play is partly de- 
pendent upon the degree of tension applied to the 



196 THE REIGN OF EUBBER 

thread while being wound. The prevailing practice is 
to stretch it almost to the breaking-point. Rubber is a 
peculiar substance, in that it is easy to stretch a con- 
siderable distance, but more and more difficult to 
stretch slightly farther distances. In golf-ball manu- 
facture the thread is put under that tension which 
brings it up to what may be called the difficultly 
stretchable part. This gives it the maximum practi- 
cal tension. Some balls are wound under high tension 
and some under lower tension. The floaters and the 
more durable balls generally, so far as the cover is con- 
cerned, are wound under lighter tension; they there- 
by have less length of flight. Because the thread is 
placed upon the core under the maximum tension, the 
high-tension balls are harder, feel heavier under the 
blow, and travel greater distances. There are many 
different kinds of winding-machines, all of them, how- 
ever, having for their purpose uniformity of tension 
and proper spherical shape. 

After the golf-ball has been wound to its precise 
size and inspected to make certain of size, weight, and 
tension, it is taken to the molding-room, where the 
cover is applied. Several methods are used. By one 
of them these covers are first formed in two hollow 
hemispheres in a preliminary molding operation. 
The mold, which is made of metal, then has one of these 
hemispheres put into it, the rubber ball placed in that, 
the other hemisphere placed on top of it, and the top 
half of the mold applied. The mold is then put into 
a hydraulic press, heated with steam, and warmed. 
When the gutta-percha is soft, the halves of the mold 
are brought together by hydraulic pressure, the action 



BROADENING THE FIELD OF SPOET 197 

forcing the soft gutta-percha into the outside layers 
of the thread and into the markings of the mold. 
After the proper time has elapsed, the steam is turned 
otf ; and, to cool the mold and the ball, water is then 
turned into the hollow plate, the 'cooling making it pos- 
sible to remove the ball from the mold without injury. 
When hot, the cover is soft ; when cold, it is hard and 
firm. After removing the ball from the mold, the op- 
erator, cuts off the slight excess of cover squeezed out 
between the two halves of the mold. 

The ball is then examined again for accuracy and is 
sent to the room where it is painted. It requires 
several coatings of paint before the right quantity is 
applied. After the ball is dried, the different colored 
paint is put into the lettering to indicate clearly the 
manufacturer's name and brand. 

There are three characteristics that make the golf- 
ball what it is to-day. It must be constructed in a way 
to give under the proper blow of a club a long and 
true flight. Secondly, it must be sufficiently hard and 
heavy so that on a putting green a fairly firm tap of 
the club is required to give the putt direction and ac- 
curacy; for a light-weight ball is inaccurate on the 
green, and in the approach shot it will bound off the 
green if too light and snappy. Thirdly, the cover- 
resistance must be sufficient to make the ball durable 
under reasonably severe playing conditions. 

The flight of a ball is influenced by several different 
conditions : the temperature of the air, the barometric 
pressure, the humidity of the air, and the wind veloc- 
ity. Golfers as a rule find wind to be the only obvious 
condition that influences their play beyond, of course, 



198 THE REIGN OF RUBBER 

their own muscles. A golf -ball is, therefore, very much 
in the position of a projectile to be fired from a cannon. 
In a recent interesting article by Innis Brown in 
''The American Golfer" a comparison is made between 
the effect of wind and air resistance upon golf -balls 
and cannon-balls. Temperature also plays a distinct 
part. In certain tests made in England, the same 
balls driven by the same mechancial device traveled on 
an average twelve yards further in May than in Jan- 
uary. A considerable part of this flight was influ- 
enced not by temperature in so far as resistance of 
cold air on the ball is concerned, but by the effect of 
temperature on the rubber thread. Rubber thread 
is snappier in hot weather than in cold. Therefore 
the flight is longer in the hot weather than in cold. 

The markings on the surface of the ball have been 
mentioned, for they influence flight very particularly. 
These influences have been studied in recent years by 
scientists, and it is now clear that different types of 
markings give different effects. Nothing flies well 
without some degree of spin; rifles are grooved in 
order to give spin to the projectile, which otherwise 
would wabble in flight. Arrows are given a directional 
character by a tail; even a kite is balanced in such a 
way that it maintains its flight, and the poorest-bal- 
anced kite is the one which wabbles the most. Each of 
these articles in the air must follow its nose, a differ- 
ence in pressure being developed upon one end from 
that on the other. 

So there is on a golf-ball a pressure greater at the 
bottom of the ball than at the top; thus the ball is 
acted upon by a force tending to make it move upward. 



BEOADENING THE FIELD OF SPOET 199 

The difference between the pressure on the two sides 
of a golf -ball is proportional to the speed of the ball 
in flight multiplied by the velocity of the spin. When 
the golf -ball leaves the face of the driver in a well Lit 
stroke, it travels at great speed. In front of the ball, 
the air is under considerable pressure; and from this 
point of extreme compression to the back of the ball, 
the air regains its normal density. Therefore, there 
is a disturbance in the atmosphere in the form of a 
tube of compressed air. As the ball travels forward, 
it creates in a constantly decreasing degree this tube 
of compressed air; and the air rushes around the ball, 
flowing in and out of the irregularities. These irreg- 
ularities thus get a, grip, so to speak, on the air ; and 
the ball is steadied in a remarkable degree during its 
flight. 

Eecently measurements have been made to find out 
how much energy is imparted to a golf -ball by the blow 
of the club. In this test various golf-balls were 
dropped from ditferent heights upon a heavy iron 
plate, which had been covered with a sheet of carbon- 
paper, so that the imprint of the flattened region of the 
ball was left on the paper. By the determination of the 
diameter and area, we learned how much the ball was 
flattened; and from this we computed the amount of 
energy required to distort the ball to that degree. 

Measurements were also made of the flattening 
given to the ball by -the blow of the driver in actual 
play. The club-head weighed fourteen ounces ; its vel- 
ocity was 203 feet a second ; the energy of impact was 
computed to be sixty-five foot-pounds. By compu- 
tation we found the velocity of the ball to be about 



200 THE REIGN OF EUBBER 

198 feet a second, and the energy stored in the ball as 
it left the club-head to amount to about sixty foot- 
pounds. This energy is equivalent to the amount of 
work one would have to do if he lifted sixty pounds 
one foot. 

Some further studies were made to find out how 
much force would be required to burst a ball when the 
load is applied gradually. Is it possible for a power- 
ful player striking the ball with accuracy actually to 
smash it? One of the standard makes of ball was 
placed between the flat steel plates on the head of a 
testing-machine and compressed. With a load of 
three thousand pounds applied to the ball, it flattened 
without breaking to the extent of more than half 
an inch. It required 3900 pounds of pressure to cause 
the ball to split open. In view of the fact that cal- 
culations show a sixty-five foot-pound force for the 
average club stroke, it is highly improbable that any 
person can burst the ball by a direct blow. 

Why is it, then, that balls break? They are not 
broken ; they are cut. The edges of mashies and other 
irons are sharp ; and when this edge strikes the surface 
of the cover with the force of a heavy blow, the cover 
cuts. Some of the golf players in this country be- 
lieve that their game would be much better if they 
used the same brand of ball favored by the accurate, 
heavy-hitting professional players. The most power- 
ful one is the harder ball, for it contains thread so 
wound that it has the maximum return force. Being 
hard, this type of ball is readily cut when topped with 
an iron club. The reason for this can be demonstrated 
by a simple experiment. If you will place a sheet of 



BEOADENING THE FIELD OF SPORT 201 

paper upon a piece of glass or any hard surface and 
press upon it with a knife-blade, you will find that it 
cuts through very easily. If you put under it a wide 
rubber band and press the blade with the same force, 
you will observe that the paper does not cut, because 
the rubber band yields. The golf-ball with the most 
resistant cover is usually the one that is the softest 
wound, for the ball inside the cover yields under the 
force erven of a cutting blow. This yielding gives du- 
rability to the cover. 

Since the long-driving, powerful ball yields less eas- 
ily to the light blow, this property permits it to be dead 
on the green, a fact which conduces to accuracy in the 
approach shot and in putting. For the average player, 
the difference in distance to be gained between the 
hard and the soft wound ball is negligible. In fact, 
the light hitter will gain more distance from the softer 
ball. The game is won, after all, by the ordinary 
golfer not on excessive lengths of drive so much as on 
accuracy in approaching and putting. We can, how- 
ever, gain longer flight by the choice of balls a little 
softer wound. 

How long should a golf -ball last? Most of them last 
until they are lost. Since the rubber thread is an ex- 
actly made rubber composition and is protected from 
the action of the air by means of the cover, there is no 
reason why the internal part of the golf-ball should 
not last for many years. The cover is durable and 
reasonably permanent; the paint is inclined to dry 
and on old balls to check when struck with a club. 
It is probable, therefore, that the present construc- 
tion of golf -balls is such that they all should last as 



202 THE EEIGN OF EUBBER 

long or longer than any player is able to use them. 

Another important use of rubber in sport is in 
the tennis-ball. A British army officer is popularly 
credited with the invention of the game of lawn- 
tennis. His original idea was a game to be played on 
a court shaped like an hour-glass, sixty feet in length 
and thirty feet in width at the base-line. Tennis is 
essentially a modern game ; its genealogy is rather ob- 
scure. The first record of any such game in Europe 
occurred sometime in the middle ages, when a crude 
form of it was a popular sport of the European 
nobles. The French game was played with a cork 
ball which was struck by the hand and driven over 
a bank of earth serving the purpose of our modern 
net. It flourished in England for a number of years ; 
and was introduced into America probably about 1874, 
when rackets rather awkward in shape were used and 
the balls were made of uncovered rubber, similar to the 
toy balls of children. The balls were later covered 
with flannel and then with felt. 

The tennis-balls now universally used are made of 
rubber of a resilient composition. This composition 
is made into the form of a sheet upon a sheeting cal- 
ender. It is then cut in sections, like an orange 
peel after quartering. Carefully cutting the edges 
at an angle or skiving them, girls cement them, 
and press them together. The ball is then placed in 
a hollow steel shell or mold. Before this, however, a 
little water or other blowing material is put inside. 
The ball is then placed in a curing-press and heated 
with steam. The steam causes the water or ammonia 



BROADENING THE FIELD OF SPORT 203 

to blow and force the rubber against the walls of the 
mold. During vulcanization, therefore, the pressure 
developed by the steam is sufficient to keep this rubber 
against the inside surface of the mold. After vul- 
canization, the ball is removed from the mold and 
gaged for size. A hollow needle is stuck through it 
at a little point where a self-healing bit of rubber ex- 
ists on the inside of the ball; through this hole the 
ball is* blown up to the proper pressure, about ten 
pounds to the square inch. The ball is then slightly 
roughened on the surface and covered with cement, 
and a layer of flannel is carefully applied. It is then 
ready for packing. 

There are several other methods of manufacture in 
detail, each of which aims at the end of exactness in 
shape, weight, size, and durability. 

The size and the weight of these balls have not been 
varied since the beginning; the laws on both sides of 
the ocean prescribe them to measure two and one half 
inches in diameter and to weigh two ounces. Great 
care has to be taken that the rubber part of the ball 
be not porous; although under the best of conditions 
nitrogen and oxygen diffuse through rubber, and the 
ball gradually loses its life. It is a remarkable fact, 
however, that of all the gases that might have been 
chosen, the constituents of air are those which diffuse 
through rubber the least readily. If carbon dioxide 
had been used, for instance, the life of the tennis- 
ball would be much shorter than it is at present. 

There is a prescribed standard of resilience. If 
balls are dropped from a height of ten feet, they must 



204 THE EEIGN OF EUBBER 

rebound not less tlian five nor more than six feet. The 
game is a fast enough one as it is, without making the 
snappiness of the ball too great. 

So one could go on with various other sports. The 
hand-ball of the gymnasium is a beautifully constructed 
spherical ball of strong, lively rubber. There are 
also the squash-balls. Polo employs a rubber ball and 
hockey a rubber puck. In foot-ball there is the rubber 
bladder inside the leather case; the players are pro- 
tected by rubber nose-pieces and ear-guards. The 
basket-ball is a sphere of carefully softened and shaped 
leather, inside of which is a rubber bladder blown up 
to tension. Even in billiards the cushions upon which 
the player depends for the return at his chosen angles 
are a most carefully worked out rubber composition of 
high resiliency and of great permanence. Here is no 
particular question of durability, for the action of 
billiards is not one of an abrasive or wearing char- 
acter, but there is a question of permanency and re- 
siliency. The moment the billiard cushion becomes 
even slightly dead, the skilled player can determine 
the fact, and the accuracy of the game is reduced. 

In the realm of sport the use of rubber products is 
essential to most games. They surely would be dead 
and lifeless without it. 



CHAPTER XIII 
POWER AND LIGHT 

One simple little thing, small in size, easy to make, 
used in thousands of forms, brings into the home, 
tamed, a mighty force. By it power to move moun- 
tains is controlled, the dark places are made light; 
by it the waters of Niagara disrupt the rocks and de- 
liver them as aluminum pots and pans into the kitchen ; 
by it coal is made to drive the trains rushing through 
the smokeless tunnels and the trolleys over city streets ; 
by it the invisible force of electricity lights homes and 
streets. It is insulated copper wire. 

Our school children scuflBe along on the carpet in 
the winter and surprise their mothers with a spark 
on the back of the neck. They play with frictional 
electricity, known in the year 941 b. c, when the 
Greek philosopher Thales, on rubbing the natural fos- 
silized resin known as amber, found that it took on the 
property of attracting light bodies, such as straw and 
feathers. From the name of the tears of Heliades, 
called "electron," came in later years our name 
* ' electricity. " 

The kind of electrical discharge, however, which 
made necessary some type of insulation is the electrical 
current that ''flows," as we say colloquially, along 
metallic conductors or wires. This type of current 

205 



206 THE EEIGN OF RUBBEE 

was discovered in 1780 by the Italian anatomist Gal- 
vani. He and Volta discovered how electrical currents 
may be generated and the fact that they flow from place 
to place through wires. 

When the induction-coil was invented, by which mag- 
netic forces could be generated through the medium of 
coils of wire, it became necessary to provide some 
means of insulation ; that is, of separation of wires, so 
that the different strands would not come in contact 
with each other and thus cause the current to flow by 
the most direct path rather than through the entire 
length of wire. When the brilliant British scientist, 
Michael Faraday, in 1831 discovered that a current of 
electricity could be induced in a coil of wire either by 
moving the wire away from a magnet or toward it, 
or by moving the magnet toward the wire or away 
from it, there began the development of that marvel- 
ous machine upon which our greatest electrical devel- 
opments rest, the dynamo, and its brother, the motor. 

The first dynamo, made in 1832, was constructed of 
a length of insulated wire wound upon two bobbins 
with soft cores. Step by step, these machines have 
grown and changed, until from them have come our 
high tensions and vast transmission systems. The fact 
that a dynamo could be reversed and run as a motor 
was known probably as early as 1838, but the value of 
this reversibility does not seem to have been realized 
until 1873. 

Now alternating currents generating at high pres- 
sure from 2000 volts up to 11,000 volts are produced 
at almost any power station. In the United States 
currents have been conveyed to places one hundred or 



POWER AND LIGHT 207 

more miles from the station, at pressures as high as 
120,000 volts. Usually, however, the generation is at 
lower voltages; for purposes of transmission they 
are changed to high voltages by step-up transformers 
and then stepped down in step-down transformers 
for use at or near the point of reception. 

Insulation is, therefore, a basic necessity in electrical 
work. The heat generated in dynamos and motors is 
too great and the space available too small to permit 
of rubber insulation. In the generator revolved by the 
water or the steam turbine, rubber is not used for wire 
insulation. The high-tension wires that stretch cross- 
country like great spider-webs are bare. But as soon 
as wires come close together in cables to lead elec- 
tricity into your house, rubber insulation becomes at 
once a necessity. Rubber is high in insulating value. 
It is strong, durable, and flexible. 

In the manufacture of insulated wire, there is a cer- 
tain procedure characteristic of this particular use 
of rubber. A trip through a wire factory would lead 
us to observe a number of cleverly worked-out proc- 
esses. A mass of copper is *' drawn," as they 
say, or forced in molten condition through a small hole 
or die to form the wire. It is passed in continuous 
lengths through a furnace, where molten tin is laid on 
in a thin layer for the purpose of protecting the copper 
from the deteriorating action of the sulphur in the 
rubber, for copper combines directly with sulphur to 
form a black sulphide. After the wire has passed 
through the bath of tin, it is coiled rapidly upon spools 
by an automatic process, in lengths usually from one 
thousand to five thousand feet. 



208 THE EEIGN OF EUBBEB 

Let us go with these spools of copper wire into a 
room where they are placed upon racks, ready to be 
covered with rubber insulation. For this purpose a 
tubing-machine is used. Unwinding from the spools 
rapidly, the copper wire passes through an apparatus 
known as the insulating head of the tubing-machine. 
The wire is drawn through two holes in either end 
of the head, each a shade larger than the wire itself. 
By the pressure developed by a slowly turning screw 
within the cylinder of the tubing-machine, the rubber 
composition, softened by warming on a mill, is forced 
around the wire. Thus, as the wire is drawn through, 
rubber is forced around it, the exact amount of rub- 
ber being controlled by the size of the die from which 
it issues. This insulating head makes it possible com- 
pletely to surround the wire with unvulcanized rub- 
ber composition. Fl"om this die, the wire is carried on 
to a machine which covers it with talc, that in the un- 
vulcanized or sticky form the wires may not stick to- 
gether. Then carefully wrapped upon a large drum, 
it is ready for the next operation, vulcanization. This 
big drum with several miles of wire upon it is rolled 
into the vulcanizer, a horizontal steel shell. The door 
closed and the steam turned on, the heat is created 
to vulcanize the rubber. This is the simplest process 
for one ply of wire surrounded by one layer of rubber. 

But there are many other grades and types of in- 
sulated wire for special purposes. When several wires 
are to be insulated from each other and all of them 
insulated from something else, it becomes necessary 
to use other methods in addition to this simple one. 
Several of these wires may be coated separately with 




Courtesy of The B. F. Goodrich Co. 

VULCANIZING HOT WATER BOTTLES 



POWER AND LIGHT 209 

rubber and then, to prevent them from spreading 
apart, they all may pass through a braiding-machine 
that wraps around them interlaced cotton threads. 
The electric light cables, for instance, which may have 
in them one ply or two plies of wire, are not only in- 
sulated with rubber, but the rubber itself is protected 
by a layer of braided thread. That, in turn is pro- 
tected on the outside by a layer of water-proofing ma- 
terial. * When two plies of wire are together, as in 
what we call the duplex cable, the construction re- 
quires a layer of rubber, then a layer of braided thread 
around each wire, then a layer of rubber and a layer 
of braided thread around the two together; in this 
fashion there may be built up many wires, each with 
its rubber insulation, with its strength-giving thread, 
and with its protection on the outside. 

Cable containing a considerable number of wires and 
all of them inclosed in a sheath of lead is made for un- 
derground work. The application of this sheath of 
lead is an interesting process, which is, as a rule, ap- 
plied before vulcanization. In a manner somewhat 
similar to the application of rubber insulation, the in- 
sulated and braided wire is carried into a lead press, 
where molten lead under high pressure and very 
rapidly applied is forced as easily as though it were 
cheese upon the rubber-covered wire, which is pulled 
through a die, leaving a quickly cooled layer of lead 
on the surface. This serves as a water-proofing and 
protecting coat, and is commonly applied to under- 
ground light cables and to telephone wires to be 
stretched over the city streets. 

One of the most important uses to which rubber in- 



210 THE EEIGN OF RUBBER 

sulated wire is put is for railway signaling purposes. 
The handling of electrical signals upon railroads is so 
vital and so exacting that it is necessary to make cer- 
tain that the wire used is in all respects uniform and 
perfect. From this has come the development of ex- 
act specifications for the insulated wire, drawn up by 
the Railway Signal Association in cooperation with 
rubber men. Where speed and number of trains are 
sufficient, the automatic block signaling systems are 
fundamental in all railway operations. Out of the 
99,360 miles of block signals installed in the United 
States up to 1919, 36,600 of them were automatic. To 
maintain the automatic system of block signals, the 
track is divided into blocks varying in length from a 
few hundred feet to several miles, the distaaice depend- 
ing on the speed of trains and the physical conditions. 
The trains operate these block signals by means of an 
electric current flowing through insulated wires strung 
along the right of way, the return circuit running back 
through the rails. The various signal circuits are 
opened or closed by contacts so arranged in combina- 
tion with signal wire as to apply electrical energy to 
the signal system when conditions are safe for train 
movement. The signal arm is counterweighted, so 
that whenever the signal circuits are deenergized it is 
thrown to the horizontal or ''stop" position. It will 
only assume the vertical or "proceed" position when 
the track is clear, a condition which means that the 
track circuits are unoccupied and all the electrical re- 
lay contacts are closed in the block over which the sig- 
nal governs the train movements. 



POWER AND LIGHT 211 

If anything should happen to the electrical circuits, 
all signals would automatically assume the stop posi- 
tion until the signaling system itself could be put in 
order. All switches on the main tracks or sidings in 
use in this automatic territory are provided with cir- 
cuit controllers. Such details have been carefully 
worked out. If the side-tracks have upon them a car 
or an engine so close to the end of the side-track as 
to foul" a main track movement, there will be an elec- 
trical reaction that will operate the semaphore stop. 
The insulated wire controlling this mechanism in all 
sorts of weather is vital to the safe operation of the 
trains ; this constitutes one of those great and import- 
ant uses to which rubber insulation is put. 

From the best of data, the first block signal system 
in this country was put into operation by Ashbel Welch 
of the United New Jersey Railroad and Canal Com- 
panies in 1863. This was considerably later than the 
introduction in England, which was as early as 1842. 
''The Scientific American" states that the automatic 
block signal was invented in 1871 by Thomas J. Hall. 

To show the degree of care which surrounds the 
manufacture of this kind of insulated wire, one may 
note a few of the items from the specifications de- 
veloped by the Railway Signal Association and upon 
the basis of which the manufacturers of wire are 
obliged to work. They vary as to quality of the copper 
wire, but insist that it be uniform in size and com- 
position. The rubber insulation must be made of a 
composition in which are used only the best of rub- 
ber and those ingredients which conduce to uniformity 



212 THE REIGN OF RUBBER 

of strength and aging properties. The braiding is 
carefully regulated; and, subsequent to manufacture, 
a series of tests is performed upon the wire to make 
sure that each coil of it has the proper strength, both 
as to wire and rubber, and proper electrical conduc- 
tivity. The wire is examined to see that the right 
amount of tin has been applied, that the braiding and 
the waterproofing have been properly done, that the 
rubber insulation is of the right tensile strength, 
and that various other properties adapting it to the 
purpose for which it is intended are present. The in- 
sulation is then thoroughly tested for electrical prop- 
erties, to make sure that there are no leaks, pin-holes, 
or other defects. Thus every possible effort that in- 
telligence can bring to bear is put on this insulation 
material to make it approach perfection. 

The wires that bring the current into your house 
are rubber-insulated in the same careful way, subject, 
however, to a slightly different code of regulations 
than have been mentioned for the railroad signal wire. 
In this case, it is the insurance companies that protect 
you; for the main risk that is run by electrical wires 
coming into the house is that of short circuits which 
might produce sufficient sparking to set fire to wood- 
work. There have been many cases known in which 
mice and rats have gnawed through the insulation of 
copper wire, causing the bare wire to come in contact 
with wood. Most modern houses have the wires car- 
ried through iron pipes known as conduits; and the 
code of regulations permits also the use of porcelain 
insulators to keep the wires a certain distance apart. 
Thus danger from lightning, from sparks jumping 



POWER AND LIGHT 213 

from one wire to another and igniting the woodwork, 
and from short circuits is avoided. 

When building a house, it is wise for a householder 
to look personally into this important part of the 
construction. Electricity is a servant when controlled. 
Be careless with it, and it may be master. Not much 
damage is done to appearance if some of the hidden 
brickwork or masonry does not strictly conform to spe- 
cifications; but it may save considerable expense if 
the electric wiring be properly installed under the 
most careful supervision and in accordance with the 
most rigid regulations that municipalities can adopt. 
Workmen may err; look over your own electrical in- 
stallation, and make sure that no insulated copper 
wire is in contact with woodwork. See that porcelain 
insulators of sufficient length are used; then you will 
be taking the most vital precaution possible in the 
building of your house — that of preventing any acci- 
dental baring of copper wire, with its subsequent short 
circuit and probable fire. 

Copper wire brings the electricity into the house; 
rubber is the protection used, and the best protec- 
tion ; for its flexibility, high insulating properties, uni- 
formity, and long life serve to make it the ideal one 
for this purpose. It does, however, gradually harden 
with age. For the user to examine carefully the 
electrical wires that connect lamps to sockets and, in 
particular, to examine the wires that connect the vac- 
uum-cleaners and other devices that are moved around 
the house, is a wise precaution. For as the wire 
wrinkles and bends, in the course of time the rubber 
may break and thereby expose the wire, the exposure 



214 THE EEIGN OF EUBBER 

leading to short circuits. One should replace these 
wires often enough to make certain that the insulation 
is always in the best of condition. 

The early dynamos produced current at low volt- 
ages of 110 to 200 volts. As the transmission lines 
were extended, the central station in a small city lost 
a great deal of power, both from heating of the con- 
ductors on account of resistance and from leakages. 
In the development of this important engineering sci- 
ence, as the years have rolled on, the voltage or ten- 
sion at which electricity is transmitted has become 
greater and greater, until to-day central power sta- 
tions, such as those at Niagara Falls, customarily send 
out over the wires electric current at many thousand 
volts, and several wires, as a rule, are strung over the 
same electric pole system. Because it is inadvisable 
to shut down all wires while the workman may repair 
one of them, proper protection is vital to his safety. 
The electrician high up on a power-line pole sur- 
rounded by death-dealing, high-tension wires is in no 
ideal situation. He must be protected against the 
power of the live wire while he repairs the dead one. 
So he throws over adjacent wires a rubber blanket 
on each side of him; and he works in security. 
These blankets are made of a highly uniform rubber 
composition ; they have high dielectric strength. Each 
one is carefully tested for its resistance to puncture 
with a high-tension current; that is, two terminals 
from the secondary coil of a high-voltage transformer 
are placed on each side of the blanket and the voltage 
is raised until the sparji jumps through. Thus the 
voltage is measured at which a spark will penetrate 



POWER AND LIGHT 215 

the rubber blanket. The blanket must resist the pene- 
tration of a spark at high voltages. 

We see the man who changes the carbons in the 
arc-lights on our city streets, as well as the repair- 
man of high tension lines, wearing rubber gloves. It 
is necessary for him to be able to handle the wires with 
impunity; certainly he could not do good work if it 
were necessary to incase his hands in porcelain gloves. 
Here Charles Goodyear comes to the front again; he 
made the first vulcanized rubber gloves to protect 
electrical linemen. Being flexible, rubber is generally 
u-sed throughout the electrical industry, where we find 
linemen and others wearing heavy gloves made of 
a pure, uniform rubber composition that is nearly 
perfect as an insulator. The lighter weight gloves are 
usually tested to resist puncturing or against exces- 
sive conductivity of current up to four thousand volts ; 
those used in high-tension circuits are thicker and are 
tested to withstand ten thousand volts. They give 
excellent service until wear and repeated creasing 
across the palms cause cracks to develop; then they 
are either repaired or new ones are purchased. 

Care must be taken in testing linemen's gloves, or 
in repairing them, for they must above all things be 
non-conductors of electricity. Each glove at the fac- 
tory is tested for breakdown or dielectric strength. 
For this purpose, a glove is placed in a copper case 
open at the top and with an opening at one side 
through which the thumb projects. The glove is then 
nearly filled with water and immersed in an iron buc- 
ket filled with water. Inside the glove and, outside of 
it, there are placed electrodes connected with high- 



216 THE EEIGN OF EUBBER 

tension current. This current is increased up to the 
point where the glove fails. 

Heavy rubber gloves are all made on fundamentally 
the same principle; that is, a form of tin or steel is 
made the shape of the hand. Workmen, usually 
women, .build sheet rubber upon it around the fingers 
and the hand. The glove is finally placed in a mold, 
pressed, and vulcanized. 

I have spoken of wire and the transmission and 
use of power. Manifold are the uses of electricity, 
and with them rubber insulation. The ignition system 
of automobiles, the hot days cooled by the swiftly ro- 
tating fan, the electrical adding-machine in factory, 
office, and store, vacuum-cleaners, the breakfast 
toaster, form a host of conveniences. We feel civil- 
ized by means of electrical power. Without it how 
bare would our lives become! And without rubber, 
we should lose the use of most electrical appliances. 



CHAPTER XIV 
COMMUNICATION 

Thff rubber hydrocarbon is a versatile substance. 
Combining with small quantities of sulphur, it yields 
soft, vulcanized rubber. It keeps its secret, however; 
for apparently no chemical compound, as the chemist 
technically terms it, is formed with any of these small 
amounts. In any event, the chemist admits his igno- 
rance as to just what soft rubber is. When thirty-two 
parts of sulphur, though, are mixed with one hun- 
dred parts of rubber and vulcanized over a long 
period of time, — six to twelve hours, — there seems to 
be formed a combination with fixed properties, which 
chemists believe to be a definite chemical compound, 
expressed by the formula CioHieSg. The compound 
is hard rubber or ebonite. 

The inventor or discoverer of hard rubber was Nel- 
son Goodyear, a younger brother of Charles Good- 
year; and the first hard rubber patent was that granted 
to him on May 6, 1851. He had assisted his brother 
in experimenting with rubber ; but he had, to this time, 
made no important contribution of his own. Because 
the need for some such substance had attracted him, he 
set out to get it. He mixed ' ' one pound of caoutchouc, 
half a pound of sulphur, and half a pound of magnesia 
or lime or carbonate of magnesia or lime or sulphate 

217 



218 THE EEIGN OF RUBBER 

of magnesia and lime." For vulcanization he speci- 
fied three to six hours or longer and a temperature of 
260 degrees or 275 degrees Fahrenheit. His specifica- 
tions claim the combining of India rubber with sul- 
phur, either with or without shellac, for making a hard 
and inflexible substance, hitherto unknown. 

Thus Nelson Goodyear was to the hard rubber in- 
dustry what his brother Charles was to the soft. On 
March 22, 1852, he granted- a license to Conrad Pop- 
penhusen for the use of his patent in making imita- 
tion of whalebone; and in July of that year he died. 
His estate was managed by a third brother, Henry B. 
Goodyear. In 1858 the patent was regranted and was 
issued in two parts; various suits were sustained in 
favor of the Goodyear patent. 

At first hard rubber was considered a substitute for 
ivory. In the early history of the business, too, the 
demand for hard rubber to incase the magnet of the 
ordinary relay and for other uses in connection with 
the telegraph field gave it a great impetus. Then it 
was stimulated by the telephone, the druggist sundry 
lines, and buttons. In 1851 the India Rubber Comb 
Co. of New York was organized for its manufacture, 
with a factory at Williamsburg, Long Island, and later 
a factory in Hamburg, Germany. 

Hard rubber and soft rubber have ever worked to-, 
gether. Probably no better illustration of this cooper- 
ation can be given than in the case of the telephone. 
It was in 1875 that Alexander Graham Bell in a Boston 
attic made the first telephone, a crude box-like affair, 
about as much like the desk telephone of to-day as the! 
stage-coach is like the aeroplane. A great many years 



COMMUNICATION 219 

elapsed before his invention came into general use. 
Now in the city of New York alone there are more 
than one million telephones in operation. 

In a recent report of the American Telephone & 
Telegraph Co. the statement is made that during the 
last ten years the investment in plant and equipment 
has increased from $672,500,000 to $1,569,000,000. 
During the last twenty years, while the population of 
this country has increased only 45 per cent., the number 
of telephones has increased about 900 per cent. In 
1921 there were more than 13,380,000 stations in this 
telephone system, constituting approximately two 
thirds of all the telephones in the world. Two and a 
half million telephones serve the farms in this country. 
At the end of 1921 there was a total of 27,819,821 
miles of Bell-owned aerial and underground wire, an 
increase of something more than two million miles 
over 1920. We are now able to telephone across the 
continent. 

It was on June 2, 1875, when Dr. Bell was studying 
transmitter rings on the telegraph instrument in the 
room of Thomas A. Watson, that the idea occurred 
to him that if the vibration could be heard over an 
electric wire so could the voice. He developed the 
idea. Great strides upon the original invention of Dr. 
Bell, but with many additions, have been made. The 
part that rubber plays is generally that of an in- 
sulator, a protecting cloak that keeps the feeble cur- 
rent within bounds and prevents it from going astray 
from the metallic path laid out for it. 

The story of the efficiency of rubber begins the 
moment you use the telephone. The instrument on 



220 THE EEIGN OF RUBBER 

the desk has much metal in its construction, through 
holes in which the wires run, but from contact with 
which they are insulated by hard rubber bushings. 
The instant the receiver is removed from the hook 
on the instrument, an electrical contact is made. The 
current, always ready in hard rubber storage batteries 
like the horses in the fire-station, flashes over the wires 
to a light at the switch-board in the exchange, thus 
signaling to the girl operator that you would have 
speech with her. The American switch-board opera- 
tors made a remarkable record during the war in 
France. They are the best trained in the world, and 
the most courteous. The operator grasps the metal 
plug, incased in its hard rubber and connected with 
its cotton (not rubber) insulated wire, and pushes it 
into a hole lined with metal in the bank of the switch- 
board and in contact with the flexible metal parts of 
the jack. The light goes out, but the electrical con- 
nection is made and you tell her your desires. These 
jacks to which the individual lines are connected are 
set in hard rubber, ten jacks to a bank. The parts 
of the jack are insulated by thin hard rubber sheets, 
about ten to a jack. Each of the thirteen million 
stations appears on a switch-board several times. 
Literally millions of little, important, hard rubber 
parts assist the accuracy of telephone conversation. 
Hard rubber is a firm, strong material, superior in in- 
sulating, properties, which with ease and accuracy can 
be sawed, drilled, or machined. The transmitter of 
the telephone on the desk and the parts of the receiver 
are hard rubber because of these very properties of 
strength and insulation. Some new substances have 




Courtesy of The Rome Wire Co. 

READY FOR THE VULCANIZER 




Courtesy of The Rome Wire Co. 

COVERING WIRE WITH RUBBER INSUL.A.TION 




Courtesy of The Rome Wire Co. 

BRAIDING WIRE WITH COTTON THREAD 



COMMUNICATION 221 

now entered this field; it will be interesting to see 
which lives. 

The wires on the telephone and the intricately ar- 
ranged forests of them on the switch-board are not in- 
sulated by rubber, or are the large lead-covered 
cables stretched from pole to pole or underground in 
tile conduits, but by cotton thread impregnated with 
wax. But from pole to house in the open, and 
from Jightning-arrester inside the house to the bell 
box, rubber-covered wire seems necessary to with- 
stand the action of light and weather. In short, where 
resistance to the elements or where the demands of 
insulation are high, rubber is the one most trust- 
worthy material. 

In no place has the rubber-insulated wire seemed 
to demonstrate its value more than during the war, 
where the part played by the telegraph and telephone 
was remarkable, — ^more so than most people realize,' — 
for the telephone connections that were strung over 
the western front by the mile were the means of com- 
munication between outposts and headquarters. In 
the World War messages over insulated wires, in- 
stantly delivered, took the place of the man on horse- 
back or the runner on foot. There were men on motor- 
cycles and there were runners on foot, to be sure ; but 
the great majority of signals and communications were 
over modern telephone systems. 

Crowell and Wilson state that the outpost wire in- 
sured secret communications at the front; it was a 
twist of two wires, each single wire being made up 
of seven fine wires, four of bronze and three of hard 
carbon steel. Stranded together, these were coated 



222; THE REIGN OF EUBBER 

first with rubber, then with cotton yarn, and finally 
paraffined. The wire was produced in six colors — 
red, yellow, green, brown, black, and gray — for easy 
identification in the field, each branch of the service 
employing its own color. 

The wastage of outpost wire was enormous. In an 
advancing movement, it was folly to stop to pick up 
the wire. Miles of it had to be left in the field to be 
salvaged later. The proposition of producing 68,000 
miles of outpost wire every month almost staggered 
the wire manufacturers of the country. Since there 
were not enough braiding machines to complete such 
an order, new ones had to be built before necessary 
production could be attained. 

Although rubber thus plays a vital part in electrical 
systems, there is one most important use in com- 
munication wherein it has failed to serve as well as its 
cousin, gutta-percha. Gutta-percha is necessary in 
532 privately owned submarine cable lines and in 2628 
government-owned lines, with a length of 56,000 miles. 
Nearly 50 per cent, of these are owned or controlled 
by British interests, a fact which may largely explain 
the great size of British foreign trade; for there is 
hardly a port in the world that a British ship enters 
wherein it cannot find a British cable office. Communi- 
cation across the sea as well as transportation upon it 
has been an enterprise in which the United Kingdom 
has ever kept ahead of its rivals. 

Atlantic cables carry four times the traffic they car- 
ried in 1913 ; Pacific cables carry nine times the traffic. 
While the armament conferees were assembled in 
"Washington in the autumn of 1921, we all recall how 



COMMUNICATION 223 

important tlie little island of Yap became in the eyes 
of America and Japan. Merely a volcanic spot on the 
surface of a great ocean, yet it was a landing point for 
a trans-pacific submarine cable, a point of intercom- 
munication of vital interest to the great nations. 

The wire man calls two or more wires bound to- 
gether a cable. He has electric light, power, tele- 
graph, and telephone cables. When they are to be 
laid under water they become submarine cables, even 
though they never see the ocean. Gutta-percha is the 
insulating material for one class of them — those that 
connect the continents. These are long, and because 
gutta-percha needs no vulcanization it may be applied 
to such extreme lengths without the necessity of vul- 
canizing several sections and splicing them together. 
Another reason for its use is its purity, no compound- 
ing ingredients are needed to improve the strength. 
It shows in the cable the low specific electrostatic ca- 
pacity of pure gum, a property of major importance 
in long cables, in which this low value permits speed 
of transmission of messages. 

On the other hand, a large number of cables are laid 
in rivers and harbors and between the islands of the 
sea. Where distances are short rubber insulation is 
used to better advantage than gutta-percha. It is a 
more reliable insulating material where a compara- 
tively high dielectric strength is necessary and be- 
cause of its better resistance to rough handling and 
to changes of temperature. Gutta-percha softens 
when hot and hardens when cold even to a greater de- 
gree than raw rubber, and it oxidizes readily when ex- 
posed to the air. Down at the bottom of the Atlantic 



224 THE REIGN OF EUBBER 

and the Pacific oceans the temperature changes but 
little, so there gutta-percha is in its element. But 
the cable around the Philippine Islands and that from 
Seattle to Alaska are rubber-insulated. The one in 
the Red Sea and the Suez Canal was laid originally 
with gutta-percha insulation; but on account of the 
very high temperature of the water in shallow parts, 
it had to be replaced by a new one in which rubber 
insulation was used. Gutta-percha became disfigured 
and soft — a condition causing irregularity in signals. 

The laying of the first Atlantic cable is one of those 
classics of enterprise in the face of obstacles. Every 
school-boy has been taught how in 1856 the Atlantic 
Telegraph Co. was formed with the object of establish- 
ing telegraphic communication between Ireland and 
Newfoundland. The first Atlantic cable was estimated 
at 2500 nautical miles in length; and after the strug- 
gles with which we are all familiar, the principle of 
cable communication came to be a proved success, al- 
though the first cable failed after a few months. The 
name of Cyrus W. Field is one to conjure with, for it 
was due to his persistence that a successful Atlantic 
cable was finally laid. In those early days a fierce 
battle was waged between the advocates of gutta- 
percha for insulation of submarine cables and those 
of India rubber. Some experts believed gutta-per- 
cha to be worthless and India rubber the only proper 
material. The test of time, however, proved India 
rubber to be too perishable a commodity for this 
purpose; in fact, it has been only within recent 
years that a degree of control of the aging prop- 
erties of vulcanized rubber has been successfully un- 




Copyright Underwood & Underwood 

AN ARMY FIELD SWITCHBOARD 




Courtesy of Western Electric Co. 

A MODERN TELEPHONE SWITCHBOARD 



COMMUNICATION 225 

dertaken. Possibly in the future vulcanized rubber 
may be used for any purpose with assurance of per- 
manency. 

Yet a new brand of communication has come among 
us. The use of the radio telephone in connection with 
aeroplanes, the development of direction finders, mak- 
ing it possible for ships at sea to ascertain in a fog 
their exact direction with reference to lighthouses, 
the use of the internal aerial in homes, and the perfec- 
tion of receiving sets, making it possible for one in 
his home to listen to broadcasted concerts, lectures, 
and reports, form one of the remarkable electrical 
developments of this age. Its end is not yet. So great 
has been radio development that confusion in the air 
has made probable a limitation by legislation of the 
number of sending stations. Since continuous waves 
of different frequencies, that is, at different lengths, 
may be sent, a classification of possibilities has been 
made, with the result that very soon the sending 
stations will probably each have its own definite wave- 
length or frequency. Thus a remarkable means of 
communication will rapidly be systematized in a way 
to avoid interference. 

Since these waves travel through the ether at the 
speed of light, 186,000 miles a second, one can sit in his 
house, tune his receiver to receive the voice of a 
speaker in a large auditorium, and actually hear the 
words more quickly than those in the rear of the audi- 
ence. Sound-waves travel at the rate of 1090 feet 
a second. A person a thousand miles away will re- 
ceive the voice in one one-hundred-and-eighty-sixth of 
the time the sound will require to reach a man a thou- 



226 THE REIGN OF RUBBER 

sand feet away from the speaker. A voice has been 
heard across the ocean ; signals have been heard at the 
antipodes. 

The part played by rubber in radio development is 
marked, for today the aerial may be made of a single 
strand of insulated copper wire instead of one made 
of a bare wire. The insulated wire throughout the 
circuits in a house, the hard rubber storage-battery 
cells, the hard rubber used in condensers, in panels 
of receiving sets, in the dials, and in other places, are 
all notable developments which assist in making the 
radio possible. 

One of the numerous uses to which hard rubber is 
applied, and one of the greatest of them in the present 
day, is the hard rubber cell for storage batteries. 
This prince of our rubber realm serves in many ca- 
pacities. When the electrical starting and lighting 
systems were developed for automobiles, they called 
for the use of a storage battery ; this has led to a high 
development of the hard rubber cell for this purpose. 
Storage batteries to supply current at even voltage 
without noise form part of the telephone system and 
of radio installation. In the earlier days, glass was 
used. But glass is too friable a substance for an auto- 
mobile running over a rough road, and too difficult 
to make precise enough in shape to economize space. 
Therefore, the hard rubber battery cell has come to be 
generally used. Its value lies in its strength and 
lightness. Some day if you will examine your storage- 
battery, which unfortunately most of us fail to do 
often enough, you will find it to be, in many cases, a 
wooden box containing three and sometimes four nar- 



COMMUNICATION 227 

row cells or boxes of hard rubber. Each of these has 
a hard rubber cover or top that fits tightly into the 
cell, resting upon a little shoulder molded into the rub- 
ber. The manufacturer of the cell then usually fills 
this space with a soft plastic composition to prevent 
the splashing over of the cell liquid. 

Whether the battery cell be of the size used in the 
automobile, — about a foot high, with a wall probably 
an eigjith of an inch thick, — or whether it be a huge 
one made for the storage-batteries of the submarine, — 
frequently five feet high and over two feet square, — 
the principle of manufacture is essentially the same. 
First there is made a lead and tin alloy, which is cast 
in a mold to the exact size desired for the inside of 
a battery jar. When this comes from the mold, it is 
called a mandrel or form. It is made four to six 
inches longer than the jar, in order to give a sufficient 
manufacturing leeway. 

After the compound is mixed, it is calendered to 
the proper thickness, and sheets of the rubber com- 
position are cut so that the length of the sheet con- 
stitutes the distance around the jar and the width con- 
stitutes its height. In the manufacture of a battery 
cell, therefore, the workman first places in the end 
of the mandrel, in the spaces provided for them, 
triangular-shaped pieces of unvulcanized hard rubber 
to form the lugs or supports for the grids or metal 
parts inside the cell. These are often known as 
** bridges." In order to have a permanent support 
for the lead members, it is necessary that the lugs be 
vulcanized to the jar. When these are put into spaces 
provided by the mandrel, the workman covers them 



228 THE REIGN OF EUBBER 

with a layer of hard rubber composition that is of the 
exact length and width of the bottom of the jar. This 
is usually somewhat thicker than the side wall material, 
because of the necessity of having the bottom well sup- 
ported. Around this mandrel, then, is wrapped the 
layer of composition, and it is carefully overlapped 
and rolled together so that no leaks can occur at the 
seam. It is then turned over the bottom part, and the 
corners are all carefully rolled down to avoid 
* leakers." 

In many of the hard rubber cells, in order to give 
them a high polish, a sheet of tin is wrapped around 
the outside of the cell after the layer of rubber has 
been applied. In some instances, the sheet of tin is 
rolled upon the side-wall composition before its appli- 
cation. Recent methods require no tin; for, after all, 
the user of the hard rubber cell never sees the cell it- 
self, and the expense of polishing it is an unwarranted 
one. After the hard rubber battery cell is thus com- 
pletely formed in its unvulcanized condition, it is 
stacked upon the shelf of a small truck, which is 
pushed, when loaded, into the shell of a horizontal vul- 
canizer. With the vulcanizer door closed, steam is 
turned in, and the cells are vulcanized. In the old 
days it required eight to ten hours to vulcanize even 
these thin layers of hard rubber ; in modern days com- 
positions have been developed which permit of vulcan- 
ization in as short a time as three hours. 

The making of the covers for the hard rubber bat- 
tery jars is a simple process. Pieces of rubber of the 
right thickness and width are placed in one side of a 



COMMUNICATION 229 

steel mold. The other side is then adjusted so that 
when, under hydraulic pressure, the two sides are 
brought together, the rubber, being soft, flows and fills 
all of the cavities in the mold. Then it is heated to 
the proper temperature and for the necessary time to 
vulcanize it into the required form. When removed 
from the mold, after inspection and trimming of the 
slight excess that has flowed from the mold into what 
is termed the rind cavity, the cover is ready for ship- 
ment. 

Eubber manufacturers make only these parts of 
the battery. The battery manufacturers assemble the 
rubber parts, together with the electrolyte, the lead 
plates, the grids, and the paste. In other words, the 
rubber man makes the rubber parts ; and the battery 
man assembles them into the battery. When the 
battery is assembled, the terminals that pass through 
the holes in the cover must be surrounded with hard 
rubber so closely that the liquid cannot splash out. 
For this purpose, as well as for a stopper between the 
terminals through which electrolyte can be added or 
removed, hard rubber is used. 

Although several different substances have been de- 
veloped to take the place of hard rubber for battery 
cell work, thus far none of them has superseded it, 
largely on account of the superior strength and light- 
ness of the hard rubber mixture. The Germans dur- 
ing the war were obliged to use other substances, 
particularly for their submarines, but without complete 
success. These large submarine battery jars are made 
up in essentially the same way as the little ones; 



230 THE EEIGN OF EUBBER 

that is, calendered sheet rubber is built up about a 
large form or mandrel until there results an unvul- 
canized jar. 

There are manifold other uses, of course, to which 
hard rubber is put : electrical switch-boards, fountain- 
pens, combs, — indeed, thousands of articles. Truly, 
in the field of communication, rubber as insulation for 
wire and hard rubber for telephone uses work in per- 
fect unison. 

Business methods of to-day, though, demand more 
than the telephone and the telegraph. Conversations 
are confirmed by mail; orders are written down; con- 
tracts are prepared and signed; records of transac- 
tions and agreements must be permanent. Memory 
is too frail a thing upon which to erect the structure 
of business intercourse. Therefore, in the office the 
stenographer is queen, where the business man is king. 
In the realm of commerce, during the reign of rubber, 
no more important servant exists than the typewriter. 

The first typewriter of which we have record was 
patented in England in 1714. In 1829 an American, 
W. A. Burt, patented what he called a ''typographer"; 
and about 1833 another kind was produced in France. 
Again in 1844 and 1846 typewriting machines were de- 
veloped in England. From then on to 1850 there were 
a number of English modifications. A. E. Beach in 
1847 constructed a fairly successful instrument, which 
utilized the principle finally worked out in the modern 
machine, that of a basket of levers arranged in a 
circle, delivering their impressions to a common center. 
He never perfected the machine, however. The 
names of Sholes, Soule, and Glidden, of Milwaukee, 



COMMUNICATION 231 

are really connected with the modern typewriters, for 
upon their ideas, developed from 1868 and 1873, 
the Remington typewriter was constructed. In this 
instrument the short arms of levers were connected by 
wire rods with levers proceeding from the keyboard. 
The paper to be written upon was passed around a 
rubber cylinder, the lower side of which received the 
impact of the type face while an ink ribbon intervened 
between the type and the paper. This is the principle 
underlying all machines as they are to-day. 

Nearly seventeen hundred patents have been granted 
on many hundred machines, each employing the 
rubber cylinder or typewriter platen. This rubber 
shell or platen is to the typewriter what the pneumatic 
tire is to the automobile. It receives the blow of steel, 
softens the shock to just the right degree, and yet is 
hard and uniform enough to permit a true impression. 

Typewriter platens are made of a peculiar sort of 
rubber composition, capable of vulcanizing neither into 
hard rubber nor soft rubber, but into an intermediate 
grade. The rubber compound can contain only sub- 
stances capable of the finest state of subdivision; no 
particles of grit must show through the surface to blur 
a letter. The platens are vulcanized to a tested hard- 
ness. If they are too soft, the impression of the letters 
upon the paper will be blurred; and if too hard, the 
paper is liable to be cut or the type injured. Through 
compounding and vulcanizing, the maker must obtain 
an exact degree of hardness. 

Would it not be comfortable if in our communica- 
tions we could compose our thoughts and exercise our 
fingers to make no errors in writing? We do make 



232 THE EEIGN OF RUBBER 

them, though, and we need to erase them. Every 
typist has erasers. In every office desk we find them. 
All school children use them. An indispensable little 
article is a rubber eraser; indeed, rubber received its 
name from its ability to rub lead-pencil marks from 
paper, the people of England calling it "Indian rub- 
ber.'' Erasing is the first successful commercial use 
of rubber on record. 

The eraser, as we now call it, is a very different sub- 
stance from the "rubber" of 1770. In it we do not 
use crude rubber only. We have improved it, and 
cheapened it. In this instance cheapening went hand 
in hand with improvement, for you would not be at all 
satisfied with a piece of crude rubber for erasing lead- 
pencil marks. It erases, yes, but not so completely as 
necessary; for the rubber itself, being too soft and 
strong, does not wear out upon the paper. In the 
practice of the years, the making of rubber erasers has 
come to be essentially the art of incorporating with 
rubber those substances that cause the mixture after 
vulcanization to wear out most rapidly. That is done 
for a purpose. As the little particles of the eraser 
wear away upon the paper, they pick up the lead-pen- 
cil marks, sticking to them so that they are removed. 
That the eraser may grip the paper tightly enough, and 
not slide over it, the proper quantity of pumice-stone 
is used in the mixture. This tears away the paper, 
roughening it and easily removing the pencil marks. 
More pumice-stone of a coarser grade is used in ink- 
erasers. In this case we not only remove marks but, 
in erasing the ink, wear away some of the paper it- 
self. 



COMMUNICATION 233 

The eraser wears out because we mix with rubber 
what is known as a rubber substitute. Men seem to 
love to find substitutes. The rubber substitute, or 
**factice/' has come into the industry for many partic- 
ular uses. When certain oils, such as rape-seed oil or 
corn oil, are boiled with sulphur, they turn dark, the 
sulphur combining chemically with the oil and thick- 
ening, after which the mass is poured into trays to 
cool and congeal. The resulting substance is a soft, 
resilient solid which may be ground into fine particles. 
The oil may be '' vulcanized" by sulphur-chloride, 
which combines directly with it at ordinary temper- 
ature. When this mixture is cooled, a light-colored, 
resilient substance remains, which we -call ''white sub- 
stitute." Incorporated with crude rubber and vul- 
canized, factice seems to have the property of breaking 
up the cohesion of rubber, forming the most valuable 
substance in making an eraser erase both itself and 
marks on paper. 

In your desk on which you write your communica- 
tions lies the rubber band. Its convenience is appre- 
ciated not only by the small boy for his sling-shot, but 
by the business man for snapping around packages. 
Rubber bands are made from pure rubber compositions 
with as little admixture of any substance as possible; 
for the one value gained from them is their ability to 
stretch as far as possible and then snap back and hold 
articles together. 

For check indorsements and the like, many men sign 
their names with a rubber stamp. Millions of checks 
pass through banks and clearing-houses with one or 
more rubber-stamp impressions on them. It is easy 



234 THE REIGN OF RUBBER 

to make any desired lettering or wording for a rubber 
stamp very quickly. Rubber stamp-making is a little 
industry by itself in every city in this country. The 
operators who make the stamps prepare molds by the 
use of what they call a matrix compound — a quick-set- 
ting mixture of mineral powders, into which, while 
soft, the impression of the steel type is forced. An 
unvulcanized rubber compound of the size and thick- 
ness desired is then laid in sheet form upon this matrix 
when it is set and dry. Pressed in a steam or electri- 
cally heated mold, the rubber is forced into the letter- 
ing in the matrix and vulcanized. After vulcanizing, 
the set of rubber type is removed, and the stamp is 
trimmed and mounted upon a sponge rubber backing 
on a wooden block with a handle. 

Rubber stamps are numerous ; in fact, they are as in- 
dispensable to the business activities of the world as 
the telephone, for they are tremendous time savers. 
Small as the stamps are, it has been estimated that 
the rubber-stamp manufacturers of the United States 
employ fifteen million dollars in capital to produce an 
annual output evaluated at about five million dollars. 

Though strikingly different in physical properties, 
each of these two forms of rubber, hard and soft, plays 
its joint part in extending the range of speech, in 
bringing ideas near at hand, and, like the brothers who 
invented them, in quietly laboring in the interests of 
mankind. 



CHAPTER XV 

FIGHTING FIRE 

''Venite, pueri, eamus ad ignem!" 

The boys of ancient Rome stood around on street 
comers, waiting for something to happen, just as our 
small boys do now. At the clang of a fire-bell, if it 
was used in those days, the boys probably rushed off 
with a ' ' Come on, boys ; let 's go to the fire. " The fires 
of Rome were not easy to put out. While the flames 
curled out of the windows, the small boys might have 
seen men stretching hose made of the intestines of 
oxen. For a fire-engine, a few men sat heavily on a 
skin filled with water, and so forced a tiny stream upon 
a second-story blaze. So says the architect Apollo- 
dorus who wrote in the time of the Emperor Trajan, 
about 100 A. D. These means accomplished little, but 
they expressed an attempt to control fire. 

The Romans probably fought fires with other crude 
engines that delivered meager streams of water 
through some kind of pipes, but history is somewhat 
obscure. Pliny the Younger speaks of the sipko as a 
fire-engine of some sort, but no hose was known. The 
ancients, even two hundred years before the Christian 
era, recognized the need and made crude engines to 
throw water. 

The earliest record of flexible hose is in the writings 

235 



236 THE EEIGN OF RUBBEE 

of Herodotus, who says that the Persian Cambyses, 
who invaded Egypt about twenty-four-hundred years 
ago, was obliged to camp in the desert, a twelve days ' 
journey from the river Corys. In order to keep his 
followers supplied with water, the monarch made pipes 
of the skins of beasts and through three different lines 
brought water to the camps. 

Concerning early use of hose with fire-fighting ap- 
paratus, Professor Beckmann, writing in 1801, says, 
**This invention belongs to two Dutchmen, both 
named John van der Heide, who were inspectors of 
the apparatus for extinguishing fires at Amsterdam. 
The first public experiments were made in the year 
1672, and were attended with so much success that at 
a fire in the next year the old engines were used for 
the last, and the engines with movable hose for the 
first time. In the year 1677, the inventors obtained an 
exclusive privilege to construct engines according to 
their principle for twenty-five years." 

Great savings were made by using the new appa- 
ratus to extinguish fires. The hose was constructed of 
leather, thick enough to withstand the force of the 
water. The leather hose was screwed upon the en- 
gine, the end of which widened into a kind of bag sup- 
ported near the reservoir, and kept open by means of 
a frame; laborers poured water into the bag from 
buckets. The Van der Heides, however, for this pur- 
pose employed a pump, which they called a "snake 
pump." How it was constructed has not been re- 
corded; it was probably a cylinder with a lever. 
Every leather pipe employed for conducting water was 
called a *' water-snake." The water-snake was not 



FIGHTING FIRE 237 

made like the hose of the fire-engine, of leather, but 
of sail-cloth. It is said, however, that for this purpose 
the sail-cloth required a peculiar preparation, which 
consisted in making it water-proof by applying a cer- 
tain kind of cement. The hose through which the 
water was conveyed had to be stiffened by metal rings 
also ; otherwise the external air on the first stroke of 
the pump compressed the hose so that it could admit 
no water. Seamless hose was made of hemp in the 
year 1720, in Leipsic, and in 1801 at Bethnal Green, 
near London. 

Apparently the first record that we have of rubber 
hose, as a definite competitor of these improved leather 
pipes was that of a hose invented by Thomas 
Hancock and manufactured by Charles Mackintosh & 
Co., of Manchester. Experiments were carried out on 
board a floating fire-engine belonging to the London 
Assurance Corporation in September, 1827. A length 
of leather hose and one of rubber were attached to 
the engine, each of them furnished with a tightly-closed 
plug. After the engine had been worked for a short 
time, the leather hose burst in the solid part of the 
leather. The India rubber hose remained firm and un- 
injured; and the engine itself became disabled by the 
breaking of one of its cranks without producing any 
effect upon the elastic material. Hancock's hose was 
made with an inner coat of unvulcanized rubber ; other 
layers were applied to the principal folds of the can- 
vas. 

It was about this time, 1829, that the first steam fire- 
engines were built in London; but they were not used 
for a number of years because of the prejudice against 



238 THE EEIGN OF EUBBER 

them. The London fire-department reported that they 
required too much water; that the water might be in- 
judiciously applied ; and that they were too heavy for 
rapid traveling. This prejudice seemed to last until 
about 1852. 

Eubber hose was a tremendous improvement. It 
was necessary to make leather hose from the best part 
of the hide. The hose was usually in forty foot 
lengths, and a great deal of the work was required to 
keep it lubricated with tallow and wax, so that it might 
remain pliable. Since rats and mice thrived on the 
leather, it was frequently soaked with infusions of 
bitter apple. Even though canvas hose had the ad- 
vantage of lightness and strength, the wet cotton had 
a tendency to decay; it would not stand rough usage, 
either. After the days of vulcanizing, at least in Eng- 
land, highly satisfactory fire-hose was made by the 
North British Rubber Co., for the use of steam fire- 
engines, which was strong and well-built, and which 
satisfactorily stood tests at the Crystal Palace in 1863. 

The invention of the hose-coupling, a most important 
part of fire-hose, came from the Van der Heides of 
Holland, who have already been mentioned. They at- 
tached brass screws to the ends of their fifty-foot 
lengths of delivery hose, so that any number could be 
quickly connected together as occasion might require. 

In America, the year 1785 saw the organization of 
the first fire company; and but a few years later, in 
Brooklyn, the first fire engine was ordered from Jacob 
Eoome of New York, who had just begun the manu- 
facture of engines in America, all the earlier ones hav- 
ing been imported from England. Great and strik- 



FIGHTING FIEE 239 

ing is the difference between the modern high-speed, 
efficient motor-engines and this most primitive water 
keg- It was a wooden box holding 180 gallons of 
water, which was poured into it from buckets filled at 
weUs and cisterns, there being no provision at that 
time for procuring water by suction. Three feet high, 
a condensing-case arose from the middle of the box; 
and the arms were placed lengthwise of the engine. 
With the handles four men could work the pumps at 
each end. From a gooseneck beginning at the top of 
the condensing case ran a six-foot pipe with a three- 
quarter-inch opening at the nozzle. Through this pipe, 
canted toward the fire, a stream could be thrown sixty 
feet. This crude thing was christened ''Washington 
No. 1.'' 

From then on, the development of fire-fighting ap- 
paratus became more and more active. The organ- 
ization of fire-departments proceeded as rapidly as 
men's minds could accustom themselves to the need 
for them and to the invention of the improvements 
necessary for the efficient combat of fire. In these old 
volunteer days, which have lived down even to the 
present, the entertainment of ''visiting firemen" 
played a social part in the life of America, as well, 
probably, as a highly influential political one. 

There have been large fires. The great London fire 
of 1666, fanned by a raging east wind, destroyed a 
city; for the only means of fighting fire in those days 
were buckets, large syringes, and crude engines. The 
great New York fire of December, 1835, shows fire- 
fighting methods in striking contrast with the modern 
ones. Then the water was so intensely cold that it 



240 THE EEION OF RUBBER 

rendered efficient working of engines impossible, and 
the fire held the mastery; the efforts of firemen were 
powerless, because water almost instantly froze in the 
engines. Even the hose lines froze. 

High-pressure water, with delivery so rapid and sup- 
ply so unlimited that it has no opportunity to freeze 
in the winter, and electric fire-alarm signals to notify 
instantly the permanent fire station of the discovery 
of the first small fire, mark the changes between the 
life of former year-s and that of to-day. Our build- 
ings are more nearly fire-proof, but enough of them 
can burn to call for speed in reporting and answering 
the fire call. 

The employment of flexible hose, strong enough to 
bear a high working pressure of water, has in no 
small degree increased the facilities with which fires 
can be fought. In particular, one must not fail to 
mention those admirable agencies, such as the Under- 
writers' Laboratories in Chicago and the Associated 
Factory Mutual Laboratories in Boston, that, in order 
to give the highest degree of uniformity to hose pur- 
chased from any one of a number of manufacturers, 
have developed specifications up to which much fire- 
hose must measure. Such great cities as New York, 
Chicago, and Boston have made careful study of it in 
cooperation with rubber manufactures, with the re- 
sult that fire-fighting rubber hose has reached a high 
state of development. 

Up to 1859 in this country, fire-hose, either rubber or 
leather, was imported from England ; but in that year 
Henry S. Herkener began the manufacture of flat, 
seamless woven hose on a few looms. He used linen 



FIGHTING FIRE 241 

yarns instead of hemp. John Clark of Maiden, Mas- 
sachusetts, had a factory for this purpose; and the 
New England Linen Hose Co. was also in the field. A 
similar hose woven by the Fitchburg Duck Co., some 
assert, was the first. This hose soon became popular 
for mill and factory purposes, and, to some extent, 
for fire-engines in the larger cities. 

About this time James Boyd's Sons of Boston man- 
ufactured at Lowell a heavy, selvage-edge duck hose, 
coating it on the inside with rubber and riveting it 
lengthwise in the lap as they had in the case of their 
leather hose. This rubber coating was put on by the 
Boston Belting -Co. Although it was a bulky, clumsy 
article in four-ply rubber construction, it was much 
used ; since the heavy working pressure of the steamers 
soon made short work of the now antiquated leather 
hose. 

Cotton flat-woven hose, rubber-coated inside and 
then turned inside out, was next manufactured. This, 
however, was a failure. By many experiments and 
much study, men attempted to find a means of lining 
this hose woven in a seamless form. Pouring rubber 
cement into the hose and drawing a metal cone back 
and forth through its length was one idea. Vulcaniza- 
tion, however, was not sufficiently well understood, and 
the fiber was injured. Various other schemes were 
invented in those days, particularly in the weaving of 
circular, seamless fabric. 

In 1872 James E. Gillespie invented a circular loom 
for weaving a multiple tubular fabric. He, together 
with Robert Cowen, a young machinist, worked out 
the fundamental ideas; but the multiple-cotton, circu- 



242 THE REIGN OF RUBBER 

larly woven hose was finally abandoned, and the single- 
jacket or straight-weave was manufactured in it,s 
stead. The need for fire-hose and the development of 
it led to the organization of many companies, among 
them the Boston Woven Hose & Rubber Co., which was 
built around the ideas of Gillespie and Cowen. J. B. 
Forsyth of the Boston Belting Co. finally patented a 
process by which the cotton, rubber-lined fire-hose was 
made possible. 

Cornelius Callahan was another pioneer. He made 
a machine for weaving cotton in tubular form about 
two inches in diameter, and conceived the idea that it 
might be used for fire-hose, although his original 
thought was of weaving woolen goods in tubular form. 
This hose was lined by the Boston Belting Co. He 
then made a fire-hose that was strong enough to stand 
the water-pressure. Callahan continued to experi- 
ment ; in 1876 he made a double-jacket hose which did 
not burst until subjected to a test at a pressure of 1180 
pounds. 

Like that of most developments, the history of hose- 
making is one of constant change, but the problem now 
seems to be settled. Rubber-lined fire-hose in reality 
consists of two parts, a cotton jacket and a rubber 
lining, the strength of the hose and its flexibility be- 
ing supplied by the jacket. This jacket is circularly 
woven, a process that means it is built upon a loom by 
which a number of cotton threads are unwound from 
spools and are woven into the hose parallel to its 
length. This constitutes what is known as the warp 
and serves the purpose of keeping the strength-giving 
part of the hose in position ; for the filling is, in point 



FIGHTING FIRE 243 

of fact, a heavy, strong cotton thread that is spirally 
and closely wound in one continuous length from end 
to end. The loom is so made that the warp or length- 
wise-threads are woven in and out among the spirals 
of jGilling. Thus, there is built a seamless, heavy, 
strong cotton tube with no rubber in it. 

The rubber lining is made of a high-grade rubber 
composition — in fact, the highest grade that the rubber 
manufacturer is capable of producing for this purpose. 
A great deal of experimentation has been done in the 
development of the composition. Because it is too 
soft, pure rubber cannot be used. The compound used 
must be stiff ; it must be strong in tensile strength, in- 
dicating the highest quality ; and it must resist aging 
to the maximum degree, for hose stands in locations 
convenient for use, not best for storage. It must also 
have those properties that permit it to adhere to the 
cotton. Since fire-hose must be in perfect condition 
when the call comes, every part of it must be designed, 
constructed, and finished accordingly. 

In order to put the tube, or ** lining," as it is called, 
into the circularly-woven jacket, the whole tube is 
sheeted on a sheeting calender to proper thickness 
and width to make up the inside circumference of a 
hose two and one half inches in diameter — the standard 
size. In the factory a fifty-foot length of this lining is 
wrapped upon a mandrel or folded over by a skilled 
workman upon a table, so as to make a tube out of it, 
the edges being overlapped and the inside being dusted 
with talc to prevent its sticking to itself. This tube 
is then carefully laid upon a long truck or metal tray, 
which is pushed into a steam heater, where partial vul- 



244 THE REIGN OF RUBBER 

canization occurs. The purpose of this operation is 
to add that degree of strength and stiffness to the lin- 
ing which will permit it to be handled in the sub- 
sequent operations without distortion or breaks. 
After this is accomplished, it is taken back to a table. 
Upon the tube is then applied a layer of rubber known 
as the backing — a soft, flexible composition used for 
the purpose of assisting in the adhesion between the 
lining and the cotton jacket. Thus, in this incomplete 
form, the hose consists of a partly vulcanized tube pr 
lining with an unvulcanized soft backing cemented to 
it. 

This rubber tube must now be drawn into the jacket 
— a trick done by a clever device something similar to 
that by which our mothers force a darning egg into 
a stocking, except that in this case the egg is followed 
by the tube. Each end of the tube is then carefully 
fastened to steam-tight pipes, and free steam is 
brought in, which at the pressure used expands the 
lining against the jacket. The heat softens the back- 
ing and causes it to flow into intimate contact with 
the cotton threads of the jacket. During the period 
of time, therefore, while steam is blown through the 
tube, the rubber vulcanizes. The result is a vulcan- 
ized rubber lining in close adhesion to the jacket. 
Ready for inspection and the application of the coup- 
lings at each end, the hose is completed. 

Out of the many articles made in the rubber indus- 
try, there are few subjected to such car efuL supervi- 
sion, testing, and accuracy of workmanship as fire- 
fighting hose. Each length is submitted to a hydro- 
static test. During this test, it must not leak, nor must 



FIGHTING FIEE 245 

the threads break; it must not contract in length or 
diameter; it must not rise from the level of the test 
table. Circular-woven hose has a tendency under 
pressure to untwist, with all kinds of peculiar move- 
ments. The manufacturer is required so to make it 
that these movements will be reduced to a minimum. 
Imagine the consternation, if not fatality, to the fire- 
men if, when water pressure of 125 pounds came hurl- 
ing through a hose, the nozzle in his hand should un- 
twist and the hose writhe. He would be thrown off 
his feet, possibly off a building. Consequently, fire- 
hose must be as permanent and free from movement 
as it is humanly possible with the best of machinery to 
make it. 

Fire-hose, too, must be as light as is consistent with 
strength. A fifty-foot length of single-jacket fire- 
hose weighs about forty pounds; and the double- 
jacket hose, such as is used with the high pressure of 
some cities, weighs about seventy pounds. Even this 
is no small weight for firemen to drag over the ground 
and up ladders. 

To make sure that each part of the hose is properly 
built, test samples are submitted to hydraulic pres- 
sure until they burst; the bursting pressure, which 
must exceed on single- jacket hose five hundred pounds 
to the square inch and on double-jacket hose six hun- 
dred pounds to the square inch, is measured. Since 
the average water-pressure of most fire-departments 
does not exceed 125 pounds to the square inch, — some 
cities run it as high as 160 and 200 pounds, but this is 
relatively rare, — the test gives a generous leeway in 
strength. Furthermore, in the system of testing, the 



246 THE REIGN OF RUBBER 

fire-departments nowadays usually follow up the hose 
purchase for the purpose of determining the life of 
the rubber composition. In addition to tests taken 
at the time and place of manufacture, for strength and 
other physical properties of the rubber composition 
used in the lining, tests are made a month later, again 
three months later, and a year later. Usual experience 
shows that if the hose stands up to the specifications 
until the end of the year, with the normal deteriora- 
tion known to be natural to rubber, it will last through- 
out the life required in the fire-department. 

Fire-hose is occasionally made, but very rarely now- 
adays, in what is known as ' ' rubber hose. ' ' This type 
consists of a rubber tube, upon which is rolled, on a 
mandrel, square-woven heavy duck that has been cov- 
ered with a layer of rubber in a friction and coating 
calender. The number of plies or layers required for 
a particular purpose is built up; on the outside is 
rolled, while the tube is still on the mandrel, a cover 
of rubber. This is then usually wrapped with cotton 
cloth and the mandrel placed in an open steam vul- 
canizer, where it is heated to vulcanize the rubber, the 
operation giving strength to the tube and the cover 
and adhesion by means of rubber between the plies 
of canvas. This rubber-covered hose is rarely used 
however, because it is too heavy. 

Fire-hose has become a basic necessity. Damage to 
property caused by the bursting of hose at fires has 
been great in the past ; delay from the same reason in 
applying water to the fire has been costly, too. This 
bursting, however, is to-day either wholly prevented 



FIGHTING FIRE 247 

or at least can be prevented by careful cooperation be- 
tween manufacturer and fire-department in the selec- 
tion of the highest type of hose and by the careful 
storage of the hose between fires. 

Since cotton is affected by moisture, decaying the 
threads and thus weakening the hose, firemen should 
always be careful to see that the hose is dry before 
replacing it on the trucks ready for the next fire. No 
questionable or bruised piece of hose should be used ; 
for th§ breaking of one strand at one point is, in re- 
ality, the breaking of the entire concentric thread, 
which, as we have shown, is wound in one length from 
end to end. And, too, rubber is perishable and must be 
stored away from the light and in as cool a place as 
possible. Even under the best of storage conditions, 
it gradually deteriorates and loses its strength. When 
old and brittle, it develops cracks that produce slow 
leaks in the hose. Deteriorated rubber is, however, 
less dangerous than torn cotton- in causing breaking. 

I wonder what will be the future of fire prevention ; 
since the losses in this country alone are startling. 
Fire-proof buildings, adequate alarm systems, hose, 
and chemical or water fire extinguishers, undoubtedly 
are means that will assist in fire prevention. And fire 
prevention is certainly a field in which the utmost co- 
operation on the part of every one can yield remark- 
able rewards in the form of money saving. 

Fire losses in the United States in 1920 amounted to 
$330,853,925. In New York City alone there were 
14,628 fires and losses of $18,806,908. Something more 
than hose is needed to check this appalling destruction. 



248 THE EEIGN OF EUBBER 

Care in building; care in the nse of electricity, gas, 
and- matches ; hose at hand in every home to catch the 
incipient fire — all these will help. 

We have equipment for efficiently fighting fire; we 
have over six million feet of fire-hose ready for instant 
use; but we need care to avoid the fire. 




Courtesy of Minneapolis Journal 

THE USE OF RUBBER HOSE AT A FIRE 



CHAPTER XVI 
IN THE SERVICE OF HEALTH 

We may succe'^d in ''outwitting our nerves,'^ but 
it is rare to find one able to keep his appendix in order. 
He whb has joined the fraternity of the appendixless 
individuals remembers well the details: the wonder 
what it was all about, the feeling that he must have 
eaten something that did not agree with him, finally 
the examination by the grave physician and the smil- 
ing surgeon. A perfectly simple thing to the doctor, 
it is a journey into an unknown land for the patient. 

Once the diagnosis was made and an operation for 
appendicitis was certain, you may remember the rub- 
ber-shod orderlies who kept you in a horizontal posi- 
tion on the stretcher, while they gently and noiselessly 
carried you down and into the waiting ambulance. 
Perhaps you were so afraid the offending member 
would cut up that you thought little of the part rub- 
ber was playing in your affairs at the time. The tires 
on the ambulance freed you from jar, — in dangerously 
acute cases an item of no small moment, for should 
that obstreperous appendix have been broken by a 
sudden shock, you would have been in for, perhaps, 
disastrous consequences. 

Your reception at the hospital was into an atmos- 
phere of quiet and seriousness. The noise-absorbing 
floors of rubber tiling, the rubber shoes on the nurses 

249 



250 THE EEIGN OF RUBBEE 

and the internes, even the rubber-tired carriage from 
the ambulance to your room, were planned in advance 
to keep you free from the irritation of noise and from 
jar or shock. These floor coverings — extensively used 
rubber products found not only in hospitals but in 
many other buildings where quiet and comfort under- 
foot are essential — are, generally speaking, classed by 
the rubber man into two groups; the one which he 
calls "tiling" and the other which he calls ''matting.'* 
The tiling is a heavy, rather thick block of material 
made in different colors and in a variety of sizes and 
shapes. The one most generally used is known as the 
interlocking tiling, which in 1896 was first made by 
the New York Belting & Packing Co. Composed of 
small blocks, the projecting ends of one piece dove- 
tail or interlock into corresponding cavities in the 
other. The composition generally used is one contain- 
ing but little rubber and a good deal of mineral matter. 
In the old days, this was done not alone because rub- 
ber was expensive, but in order to give stiffness and 
to permit purity of color. The more mineral matter 
used, the purer the color. Even though rubber is to- 
day one of the cheapest ingredients, tiling is still made 
with little rubber and much mineral matter. Yet color 
and firmness are so vital that rubber tiling has become 
one of the more expensive rubber articles. 

The other type of floor covering is matting. Fre- 
quently it is used for stair treads, because it may be 
removed for cleaning. Sometimes it comes corrugated 
or in the form seen in Pullman cars, in little blocks of 
different colors that have been put together on a strip 



IN THE SERVICE OF HEALTH 251 

of heavy fabric. Matting is rubbery and thin ; and it 
is made, in the case of corrugated matting, in long 
sheets to be rolled and cut up to the size and shape de- 
sired. The thicker pieces or mats at one's door-step 
are heavier, with cut-outs or spaces. Vulcanized in 
molds, the cavities of which are of the thickness of the 
material desired, the mats are designed by a workman 
with a die that cuts out the spaces of the pattern. 
There are many different kinds of mats and matting; 
in the Hospital, however, the floor covering that we call 
tiling is the one most generally used. 

But let us come back to one's self as a patient, and 
consider many of the things that make the hospital 
what it is to-day. In case of an emergency operation, 
the surgeon would probably order the removal of 
everything you had in you. If so, he would call upon 
the stomach-pump to take out that last dinner you had 
eaten, in which case a rubber tube, with a bulb rubber 
pump at the end, would be slipped down your throat. 
To drain the intestines, he would probably give you 
an enema, using a rubber fountain syringe with its rub- 
ber tubing and hard rubber tip. 

In every detail of the preparation for your oper- 
ation, you could scarcely get along without rubber. 
Again you would be laid carefully upon a rubber- 
wheeled stretcher, and this time be pushed along into 
the room adjacent to the operating-room, where the 
kind-hearted anesthetist would see that you were 
quietly put into the deep sleep afforded by ether. 
Then, happily you cannot see the things the surgeons 
use ; but under other circumstances, you might appre- 



252 THE EEIGN OF EUBBER 

ciate the role that rubber products play during the 
operation itself. 

The practice of modern surgery constitutes one of 
the greatest advances for the well-being of humanity. 
There is a tremendous difference between the old meth- 
ods and the new. Surgery has been performed for 
hundreds of years, war, if nothing else, necessitating 
it. Amputations were necessary. In the days of Hip- 
pocrates and of the Arabian physicians, there was 
little done in the way of cutting for fear of hemor- 
rhage. Affected parts usually become gangrenous and 
were removed only when they virtually fell off. One 
marvels at the fortitude both of surgeon and patient 
during the middle ages, when, to prevent hemorrhage 
in amputations, the cautery was used. Imagine the 
contrast with the methods of the present operating- 
rooms. In those days, with no anesthetic, the poor pa- 
tient lay in the operating-room,.such as it was, awake to 
all that happened. Cauteries were heated in the fire in 
another room. Yet, however careful the surgeons were 
to hide the apparatus, one can imagine the pain and 
the shock of such operations. 

Ashhurst in an address entitled **The Patience of 
Surgery" makes the remark that *'Esmarch (1873) 
introduced his rubber tube and inaugurated an era of 
absolutely bloodless surgery." While we must not 
give rubber the full credit for changes in operative 
surgery, yet it came to be one of those important tools 
which contributed to the technique of the surgeon. 

No one who has been brought up in the school of 
antiseptic or aseptic surgery can have any idea of the 
horrors that were perpetrated in the name of surgery 



IN THE SERVICE OF HEALTH 253 

by our ancestors. The lack of anesthesia in those 
days perhaps was an advantage rather than otherwise, 
as it limited the scope of operations. During opera- 
tions, patients had to be forcefully restrained. The 
wards were hotbeds of surgical fever and other mani- 
festations of unsanitary methods leading to an appal- 
ling post-operative death-rate. Alleviation of pain 
came with the discovery of anesthetics (1842-46), in- 
volving the names of four investigators — Long of 
Georgia, Morton of Hartford, Wells of Hartford, and 
Jackson of Boston, who began to use ether and nitrous 
oxide. Finally, chloroform was used in 1847 by Simp- 
son in England. 

Despite the fact that bacteria were discovered by 
the Dutch optician Leeuwenhoek of Delft in 1683, and 
studied further by many men, including Schoenlein in 
1839, Holmes in 1843, Oohn in 1850, and Pasteur in 
1858, it remained for the great Lister to apply the 
knowledge to operative surgery. 

Micro-organisms of various kinds, both pathogenic 
and non-pathogenic, are minute vegetable cells that 
cause us much trouble. Early in the hospital expe- 
rience of Lister in England he had been deeply im- 
pressed with the high mortality from septicemia, ery- 
sipelas, tetanus, and hospital gangrene. The fatal 
cases were numerous. Those were the days of *' laud- 
able pus"; yet when his attention was drawn to the 
work of Pasteur, he set out to prevent the develop- 
ment of micro-organisms in wounds. At that time 
gangrene was so common that without pus and sup- 
puration surgical operation was considered inefl&cient. 
Where he perceived that sterilization would avail 



254 THE REIGN OF RUBBER 

nothing, he turned to chemical antiseptics; and, by a 
lucky chance he hit upon carbolic acid. He employed 
it with success; and, although subject to a great deal 
of criticism, he developed his idea and labored con- 
tinually to improve his dressings. 

From this idea modern antiseptic surgery has grown. 
The day of the bare-handed surgeon began to disap- 
pear. To-day when the time comes for an operation, 
the surgeon and his assistants put on duck trousers 
and thin, short-sleeved shirts of white muslin. They 
sterilize hands and forearms ; they envelop themselves 
in gowns -that have sleeves long enough to cover fore- 
arms and wrists; they wear sterile caps; and many 
operators even wear respirators over nose and mouth 
to avoid the possibility of saliva or mucus being pro- 
jected into the wound. 

While Lister believed that the chief danger from 
micro-organisms came from the air, it is now known 
that the real risk is from actual contact of hands, 
instruments, dressings, or foreign bodies. Therefore 
all of the things used are sterilized. Most surgeons, 
however, are so much impressed with the impossibility 
of sterilizing bare hands that they wear gloves in 
operations. More than sixty years ago at King^s 
College, Sir Thomas Watson in a lecture suggested 
that obstetricians wear gloves. Some surgeons had 
used cotton and others silk gloves, but cotton and silk 
are not impervious to micro-organisms. Because rub- 
ber is impervious, to-day we find the operative surgeon 
using thin, seamless rubber gloves. 

After gloves are sterilized by boiling, they are dried 
and kept in a sterile towel until ready for use. Every 



IN THE SERVICE OF HEALTH 255 

precaution is taken by the surgeon when putting on 
the glove that nothing comes in contact with it. It is 
placed upon his hand just before the operation is to be- 
gin. Even during the operation, should the glove come 
in contact with any infected object, a clean glove is 
substituted. These rubber gloves, to be sure, some 
what impair the sense of touch; but the surgeon has 
become so used to them that, except in rare conditions 
where the danger of contamination is remote, gloves 
are use'd. One great surgeon states, ''I always wear 
gloves"; but that it is absolutely necessary to wear 
gloves in all cases has not been proved. The rubber 
glove serves to protect the surgeon as well as the 
patient from infection, both during examinations and 
operations. 

Dr. William S. Halsted of New York, who when a 
professor of surgery in Johns Hopkins University, 
Baltimore, made many important advances in surgical 
practice, was the first to use rubber gloves. He says 
that he was led to do so in 1889 by reason of his ex- 
periments on the disinfection of the hands and the skin. 
Since it was virtually impossible to sterilize them, he 
adopted the use of rubber gloves, a practice that has 
continued from that day to this. 

Because these gloves constitute one of the funda- 
mentals upon which modem antiseptic hospital 
practice depends, it is interesting to consider how they 
are made. All of them used for this purpose are con- 
structed by what is known as the ''dipping process." 
Surgeon's gloves, toy balloons, and nursing nipples 
constitute virtually the entire output of dipped-goods 
factories. In the manufacture of dipped goods, only 



256 THE REIGN OF RUBBER 

tlie cleanest, finest grades of rubber (smoked sheets, 
pale crepe, or up-river fine para) can be used. Before 
it is started through any process, the manufacturer 
takes excessive care to see that this rubber is free from 
dirt, chips, or any foreign material; for these little 
particles of foreign matter would cause holes, and a 
hole in a surgeon's glove makes it useless and brings 
danger both to the surgeon and the patient. There- 
fore it is customary to wash this rubber with great 
care and to dry it by the methods which maintain the 
maximum of its natural toughness and resiliency. 
The rubber is masticated for a long enough time, in a 
mixing-mill that is comfortably warm, but not hot. 
Modern chemistry has shown that masticated rubber 
or rubber softened by mechanical action readily forms 
a thin cement when mixed with a solvent. In making 
surgeon's gloves, in order to limit the number of dip- 
pings required for a given finished thickness, it is ad- 
visable to have a well-softened rubber. 

In the case of toy balloons some coloring material 
is used, red, blue, yellow; but in the case of surgeons' 
gloves no color of any kind is utilized. For a solvent, 
a pure grade of gasolene is employed, but one that 
does not volatilize too rapidly. It must be pure and 
free from waxes and high boiling ingredients, for these 
would be left in the rubber after evaporation. In the 
best factories, the rubber, after weighing, is cut into 
pieces of convenient size and placed in a fairly large- 
sized, revolving, drum-like apparatus known as a ce- 
ment mixer. This is tightly sealed to avoid loss of 
solvent. As the gasolene swells it, paddles inside pull 




THE DIPPING MACHINE OPENED TO SHOW ONE RACK OF GLOVES READY TO BE DIPPED AND 
ANOTHER RACK ABOUT HALFWAY SUBMERGED IN RUBBER SOLUTION 




THE ENCLOSED DIPPING MACHINE WHICH KEEPS THE CEMENT AND THE GLOVES FREE FROM 

DUST 




Photos by courtesy of The Faultless Rubber Company 
IN THE FINISHING DEPARTMENT, TO SHOW OPERATORS ROLLING AND BINDING GLOVES 



IN THE SERVICE OF HEALTH 257 

and tear the rubber, which, gradually becoming weaker, 
forms a sticky ma&s of cement. 

In a tall tank the cement stands about twenty-four 
hours, until any impurities have settled. The solution 
in the upper half is drawn off and strained through a 
fine-mesh brass wire screen. Then the cement is car- 
ried on to a tank called the ** dipping tank," in con- 
nection with which is used' a machine known as a 
"dipping machine." Dipping machines are simply a 
series oT frames arranged over the tanks in such a way 
that one frame can be dropped slowly down into the 
cement, allowed to remain a proper time, and removed. 
They carry upon racks, porcelain forms that look like 
human hands. A aeries of different sizes are made, 
numbered usually from six to ten, with half-size inter- 
vals; although seven, seven and a half, and eight are 
those most generally used. In operating the dipping 
machines, which may be either intermittent or continu- 
ous, the forms are placed with the fingers down upon 
racks on the machines. The forms are slowly forced 
into the cement, where they are allowed to rest a 
moment, and then are removed. With the layer of ce- 
ment upon them, the forms are allowed to stand in the 
air of a room to dry. At the end of about two and a 
half hours, they are dipped again. Thus a thin layer 
of rubber is deposited uniformly upon the form. The 
operation is repeated from six to ten times, until the 
proper thickness, by this repeated dipping and evap- 
oration, is built up. 

Because the tacky, sticky, half-dried, unvulcanized 
gloves are easily contaminated by dust, insects, or 
particles from walls or ceiling, the dipping room must 



258 THE REIGN OF RUBBER 

be clean. A well-planned system of ventilation carries 
out the solvent vapors and replaces them with fresh 
air, without, however, the introduction of foreign ma- 
terial. The gloves must be perfectly dry before they 
can be passed on to the vulcanizing stage of the proc- 
ess. Such conditions as humidity and temperature 
in the room are controlled by automatic devices in the 
best factories. Suitable thinness or proper thickness 
of cement is another important matter cared for by 
watchfulness on the part of workmen. 

The final drying, which follows the last dipping, 
eliminates all solvent. Depending upon the weather, 
the drying time usually varies from eight to twenty- 
four hours. When conditioned air is used, it is reg- 
ulated to a schedule. Because dipped goods, like all 
other rubber products, are made in definite weights, 
careful standardization is attained in the dipping 
room by test-weighing materials stripped from forms 
as the dipping nears completion. After the dipping 
and the drying of the gloves in a finishing room, such 
refinements as beaded edges are applied, either by 
hand or machinery. 

Vulcanization is accomplished by one of two meth- 
ods. Surgeons' gloves are usually vulcanized by ex- 
posure, in a special room arranged for that purpose, 
to the vapor of sulphur chloride at a temperature of 
about 180° Fahrenheit during a period of one hour. 
This is a practical application of the cold cure or 
Parkes process. During vulcanization it is in foggy 
weather very difficult to keep moisture away. Every 
care is taken to do so, for sulphur chloride is rapidly 



IN THE SERVICE OF HEALTH 259 

decomposed by moisture, with a separation of sulphur 
and the forming of hydrochloric acid. However, some 
forms of dipped articles are vulcanized in a bath con- 
sisting of a solution of sulphur chloride either in ben- 
zol, carbon bisulphide, or carbon tetrachloride. This 
is a weak solution of about 2 to 4 per cent., in which the 
article to be vulcanized is dipped and allowed to re- 
main for a time varying from fifteen to sixty sec- 
onds, depending upon the thickness of the rubber. 

After they have been vulcanized the gloves are taken 
to a stripping and inspecting room, where they are 
removed from the forms, dusted with soapstone, 
tested to be sure that they are free from imperfections, 
and packed for shipment. 

Surgeons' gloves are the finest article of the kind 
made. By this dipping process they come to the hos- 
pital seamless, with wrists usually reinforced by rub- 
ber tape or cord. Since the vulcanization was per- 
formed by sulphur chloride, they are entirely free from 
any hard substances inside the rubber. This not only 
serves to limit the danger from puncture, but naturally 
renders true the sense of touch. They are smooth, 
although some have been made with a finely pebbled 
surface. For special purposes, many of them are 
made with long sleeves. 

During the course of an operation there are a num- 
ber of other rubber articles that play important parts. 
Although I have concentrated upon gloves, there are 
solutions of specially prepared sterile rubber which 
may be applied over the cutaneous surface and thus 
prevent the spread of infection. The commonly used 



260 THE EEIGN OF RUBBER 

protectives developed by Lister included not only silk 
protectives, paraffin paper, and so on, but rubber mem- 
branes and gutta-percha tissue. 

It is a long way from the modem, beautifully kept 
hospital to the surgery practiced during the World 
War, with the sudden changes from place to place be- 
cause of troop movement and the exigencies of battle. 
It is also a long distance in the practice of surgery 
from the methods used in the World War to those 
used in the Civil War in this country or in the Euro- 
pean wars during the middle of the last century. Ash- 
hurst, writing about the great French surgeon Nelaton 
(1807-73), remarks upon his wonderful discoveries. 
He had the characteristics that have endeared modern 
surgeons to thousands of patients ; for he stood at the 
turning of the ways between the brutality, necessary 
possibly, of the older method and the gentleness and 
refinements of the new. Ashhurst says : *' He wished 
surgery to be gentle, and he was happy to think 
that the patients who forget in after life the 
pangs surgery had made them endure, retained an af- 
fectionate memory of the surgeon." He invented, 
for instance, the soft rubber catheter now in universal 
use. It was during his time that Chassaignac intro- 
duced the rubber drainage tube (1859). The old war 
methods were crude; if they were brutal, it was be- 
cause the facilities that have marked the more gentle 
modern surgery were lacking. 

As a good illustration of the difference between the 
early wars and the present ones, it is of interest to 
know about the illustrious Garibaldi, who was 
wounded in August, 1862. The best Italian surgeons 



IN THE SERVICE OF HEALTH 261 

''explored the wound. '^ Exploration of a wound 
meant a painful probing process. They failed to find 
the ball, and this great general lay for two months in 
an uncertain condition. Finally it was only by the 
use of Nelaton's porcelain-tipped sound that the ball 
was located, where he had predicted. Imagine the 
change from those old methods to the ones in the mod- 
ern wars, by which the location of any foreign matter — 
pieces of shell or shrapnel — is immediately discovered 
with the X-ray apparatus. Frightful as the World 
War was, it would have been infinitely more so without 
these many refinements ; and the X-ray, while definitely 
a discovery in pure physics, is assisted in no small 
way by rubber insulated wire. 

The use of rubber tubing to convey antiseptic so- 
lutions had its most marked advance during the World 
War. Many is the soldier who owes his life and 
health to the Carrel apparatus for administering 
Dakin's solution. The perfection of the Carrel-Dakin 
technique was the most marked advance in the treat- 
ment of infected wounds since the discovery of anti- 
septic surgery. The experience gained during the last 
fifty years from civil, military, and industrial surgery 
had contributed very little toward the combating of 
wound infection. Because of the character of the 
wound and the nature of the infection, the extent of 
damage in the great war was far more deep-seated 
than in previous wars. So the problem which con- 
fronted Carrel and Dakin was the same as that which 
confronted lister. They worked out a mtethod ofj 
bathing tTie infected wounds with a constantly flowing 
solution. To accomplish the greatest facility in bath- 



262 THE EEIGN OF RUBBER 

ing wounds of different types, it was natural for them 
to turn, as men have for years, to rubber and to rub- 
ber tubing as the most flexible tool. Without rubber, 
imagine the difficulty of twisting glass to shapes nec- 
essary for the treatment of all kinds of wounds. 

It would be impossible here to catalogue the mani- 
fold uses and services to mankind achieved by rubber 
in army medical work. It plays its part in a general 
movement emanating from the minds of men in the 
field of surgical and hospital practice to make the 
patients' lot endurable. 

To return to our appendicitis operation, let us imag- 
ine the patient in the quiet of a clean, white room, be- 
ginning to recuperate. We have spoken of the rubber 
drainage tubes, but we find also the hot-water bottle, 
the ice-bag, the sheeting on the bed, the elastic band- 
ages, the movements of chairs and beds rendered 
noiseless by rubber tips, all tending to make him more 
comfortable. 

Since in the advance of medical practice, as in all 
other paths of life, the use of new tools to gain the 
end of comfort and health is probably one of the most 
important services to be rendered, let us keep our eyes 
open to the results of the present and search on for 
new attainments. In the words of Ashhurst: 
* ' To know the wisdom and the accomplishments of the 
past, and from them to gain a clearer vision of the 
needs and the possibilities of the future; to record 
and to study the experiences of the present, and com- 
pare them with the learning of others; to recognize 
the shortcomings and the disadvantages of current 
methods and theories, and to search for better; to let 



IN THE SE"RVICE OF HEALTH 263 

neither feeble health nor prosperity, neither the 
indolence of youth nor the procrastination of advanc- 
ing years deviate them from the path of learning 
and of progress; to prove all things and hold fast to 
that which is good : This is the patience of the saints. 
This is the patience of surgery." 

May rubber ever play a strong, vital part in the 
service of health ! 



CHAPTER XVII 
BELTING, PACKING, AND HOSE 

Belting, packing, and hose are the rubber trium- 
virate in mines, mills, and railroads. Machinery must 
be driven from prime movers, boilers' must be steam- 
tight, railroads must run in safety. 

For the transmission of power, the rubber belt came 
into use in relatively recent years. Probably the 
first time was in 1844, when two Englishmen, Alsap 
and Forster, patented improvements in elastic fabric 
as driving bands for machinery. Again, in 1858, an 
Englishman named Parmalee worked out the principle 
of stitching together two or more layers of woolen ma- 
terial which had been previously spread or coated on 
both sides with India rubber or gutta-percha. A 
basic patent, this was for many years known as Parma- 
lee belting. 

Modern factories contain forests of belting. Where 
the operations of the machines are variable with re- 
spect to load, the electric motor connected directly 
to machines has not displaced belting. 

In the woods of Maine or in the far Northwest, the 
planers and the great saws of the lumber mills slash 
their way through wet timber, impelled by power 
transmitted through rubber belting. Here, with vari- 
able loads and wet lumber, conditions are not at all 
favorable; and rubber-covered belting alone seems to 

264 



BELTING, PACKING, AND HOSE 265 

stand the irregular service. Of all the types of ma- 
terials used for the transmission of power between 
moving parts, rubber belting is capable of widest ap- 
plication under conditions ranging from the frigidity 
of winter's cold to the boiling of summer's heat. 

Belting is a combination of rubber and strong, tough 
cotton fabric. The cotton fabric is the backbone of the 
belt. The rubber compositions, the sinew and the' 
muscle, hold the layers of cotton together and cover 
them to'give friction-grip upon the pulleys and to pro- 
tect them from wear and weather. 

In the design of belting the number of layers or 
plies of duck and the width and length necessary to 
transmit the amount of power required with a mini- 
mum of loss and a maximum of life must be deter- 
mined. With these data, one who understands belt- 
ing can design it for any purpose, in a way that will 
give the longest possible life and the most uniform 
service. Herein lies one of the evident advantages of 
the cotton-rubber belt — flexibility of design. Given 
the most difficult installations, a rubber belt can be 
made to fit them. 

The most important, probably, of the belting com- 
positions is the layer of rubber between the plies of 
cotton duck. We shall not stop to consider how any of 
the compositions is mixed ; nor is it necessary to men- 
tion the constituents. Belt duck usually comes from 
the cotton mill forty inches to fifty inches wide, de- 
pending upon the design and the purpose for which it 
is intended. It is wound in long rolls upward of 150 
yards in length and weighing about three hundred 
pounds. 



266 THE REIGN OF EUBBER 

The rubber composition for the belting is softened 
on a warming-up mill. If it were fed to the friction 
calender when cold, it would be too hard to flow, even 
at the ordinary summer temperatures; therefore be- 
side the big calender are mills very similar to the 
mixing mills in the mill-room. Upon these an opera- 
tor places pieces of the mixture. The rolls squeeze 
and work them until they are soft. Pieces are then 
cut off and placed between the two upper rolls of the 
calender, which move at a slow, steady speed. This 
causes the rubber to be sheeted and passed around in 
direct contact with the middle roll. The space be- 
tween the middle and the bottom rolls is kept at just 
that amount of separation which will permit the thick 
cotton fabric to pass between without crushing. On 
the way through, the rubber compound is forced 
against it and into the interstices between the threads. 
It is wound upon a drum on the opposite side. 

Since the middle roll of the calender is moving at 
a faster speed than the fabric, it gives the fabric a 
wiping action in passing. Because of this the calender 
is known as a "friction calender"; and the operation 
of applying rubber to cotton duck is called "friction- 
ing." Thus, the first process in preparing belting is 
to friction the fabric with the proper rubber composi- 
tion. 

Rubber is applied in this way to each side of the 
long roll of duck; then an additional coat of rubber 
is laid on. Rolled up again for ease of carrying, with 
a layer of cloth between the plies to prevent sticking, 
the rubberized fabric is transported to the belt depart- 
ment. In the belt department the operators measure 



BELTING, PACKING, AND HOSE 267 

off the required length and width ; and by a systematic 
method of procedure they lap one layer upon another 
until the requisite thickness is built up. Each ply 
from top to bottom is balanced with respect to width 
and relation to each other ply, so that the belt in bend- 
ing around the pulley will work as a unit. 

The belt is then taken to long vulcanizing presses 
heated by steam. Here rolls of uncured belting are 
supported at one end of a long hydraulic press. 
Several strips of narrow belting together are drawn 
through the press upon the surface of the lower plate 
or platen. Through hydraulic pressure this lower 
platen is raised, so that the belting is gently squeezed 
between these two steam-heated, polished, hollow steel 
platens. To prevent squeezing it too heavily, guides 
or metal strips of proper thickness are laid upon each 
side of the belt. After a period of time which varies 
according to the thickness and size of the belt, the rub- 
ber is vulcanized. Then the hydraulic pressure is re- 
lieved, the press plates are separated, and another 
length of belting is pulled through. Thus, section by 
section, the roll of belting is vulcanized and wound up. 

Vulcanization, however, has accomplished the pri- 
mary purpose of creating a degree of resistance to sep- 
aration of the plies of cotton cloth, that in action pre- 
vents pulling apart. Obviously this is the one im- 
portant function that rubber performs, and herein its 
peculiar character is again remarkably well demon- 
strated. There is no other material which applied in 
any way gives to such layers of cotton the two prop- 
erties necessary for service. These two properties 
are adhesion and flexibility. 



268 THE EEIGN OF RUBBER 

One cannot be greatly dissatisfied with rubber when 
he hears of the case in one of the lumber mills in the 
State of Washington, where a fifty-six-inch- wide, eight- 
ply transmission belt ran from October, 1905, until 
April, 1917, or nearly twelve years, although its top 
cover was torn off by accident and it was twice sub- 
merged in water during flood times. During this 
period it transmitted 26,000,000 horse-power-hours. 
This is equivalent to an amount of work sufficient to 
move a mass of one ton 211 times around the earth. 

Rubber belting has been manufactured in the United 
States since 1836, even before vulcanization was dis- 
covered. It was later a monopoly under the Good- 
year patent, controlled by Henry Edwards of Boston. 
It became one of the important lines manufactured by 
all the leading rubber goods producers. 

Since every fiber can be governed during the process 
of manufacture, rubber belting is uniform in make-up. 
The duck is tested ply by ply and foot by foot. When 
the belt is finished, its ''friction" can be governed and 
tested. Where a belt is required actually to run in 
water, as is the case in mines and concentrating-mills, 
the rubber belt has merited its extended use. Like 
tires, footwear, and other goods, the modern rubber 
belt is the result of remarkable evolution in manu- 
facturing. The early belts had the inherent faults of 
a product of an undeveloped industry ; but after years 
of experimentation and study, the virtually perfect 
belt of to-day was found ; and it has become a valued 
article wherever power transmission is needed. 

One important phase in the application of the rub- 
ber belt is the fastening of the ends. Proper fasten- 



i 



BELTING, PACKING, AND HOSE 269 

ing permits the maximum amount of power to be trans- 
mitted. It means a steadier drive and freedom from 
jerks, flapping, vibration, and side-sway; for the belt 
it means less wear and longer life. 

There are various types of lacings to hold the ends 
together. Endless belts are built for special pur- 
poses ; but they are often made in the field by cutting 
back the several plies and lap-splicing them, using rub- 
ber cement and either vulcanizing on the spot or dry- 
ing under pressure. 

Underneath the Pullman car, pelted by cinders and 
sand, in winter ^s cold and summer ^s heat, runs a belt 
that affects us when we travel. It is the axle-lighting 
belt, connecting a pulley on the axle of the truck with a 
pulley on the dynamo that generates current for the 
lights in the cars. It runs continuously day and night, 
in all kinds of weather. The service is most severe; 
yet test records show that many of these belts have 
run more than forty thousand car-miles, and some 
more than one hundred thousand car-miles. 

Belting for power transmission is the little fellow 
but the eldest of the family. The younger brothers 
are larger of stature. They are the burden bearers, 
for upon their backs are conveyed materials of all 
kinds. In the mines and smelters in any of the great 
mining centers of Montana, Utah, Colorado, Arizona, 
or anywhere in the world, slow-moving, heavy con- 
veyor belts transmit ore from crusher to concentrator 
over relatively long distances. 

Thomas Eobins was the pioneer of conveyor belts. 
He made a suggestion that apparently revolutionized 
the conveyor-belt design. Believing that a rubber 



270 THE EEIGN OF EUBBER 

cover would outlast many times its own thickness of 
cotton fabric, he conceived the idea of a belt with a 
thick layer of rubber on one side. After making nu- 
merous compounds and testing them with a heavy 
stream of ore, he found one that would stand abrasive 
wear for the longest time. From then on, he devel- 
oped the idea of idler pulleys and the trough-shaped 
belt, so that, in point of fact, the ore was continuously 
in motion, carried in a moving trough. This idea was 
the best fundamental conception of a conveyor belt. 
After a good deal of difficulty, he succeeded in interest- 
ing people in the conveying of iron ore and also of 
anthracite coal. 

Conveyor belts are made on essentially the same 
principles as transmission belts. Heavy cotton can- 
vas, frictioned and coated with rubber, is built up in 
several plies, so as to be flexible and contain the rub- 
ber best able to resist wear. But the rubber is thicker 
in the center and the fabric thicker at the edges. 
Thus, the most rubber is concentrated where it will re- 
sist wear; and the most fabric is placed at the edges, 
where it will carry the strain of power. The belts 
are easily moved; they may be given concave or flat 
surfaces, as the conditions demand; they are light in 
weight as compared with metal buckets; they show a 
minimum of wear from friction on the rollers, as com- 
pared with buckets traveling in chutes : all these prop- 
erties have made extensive installations of conveyor 
belts a necessary part of many mining operations. 
The design of these belts for special purposes is a mat- 
ter of engineering construction and is different with 
nearly each installation, for various kinds of ore, for 



BELTING, PACKING, AND HOSE 271 

particular speed, for the weight and the type of ma- 
terial. The duck must be strong and flexible, and the 
rubber adhesion must be maximum during the life of 
the belt. The rubber cover must resist heat, for many 
materials are hot ; it must resist abrasion, for the ore 
particles are sharp-edged. 

In the mines of the copper companies in Salt Lake 
City, there are installations of belts three hundred and 
more feet long, a yard wide, which have delivered more 
than seven million tons of ore. In conveying sugar in 
California from evaporator to warehouse, belts four- 
teen hundred feet long and thirty-six inches wide have 
operated continuously over nine-year-periods and de- 
livered during that time eight billion pounds of sugar. 
To charge gas retorts, belts carry coal from bin to 
charging machinery over distances as long as thirteen 
hundred feet. Some belts weigh more than fourteen 
thousand pounds. The presses in which these giant 
workers are vulcanized have, in recent years, grown 
to thirty feet long and eight feet wide. 

It was difficult even a few years ago to convince the 
mining engineers that so soft and resilient a material 
as rubber could withstand the abrasive action of stone. 
Such a supposition seemed unreasonable, but the test 
of the actual use of rubber in comparison with metal, 
leather, and other materials has demonstrated that 
under this cutting and abrasive action it outwears by 
several times any other substance. The rubber-sur- 
face conveyor belt has come to be the most efficient 
means of handling sharp-edged material. It carries 
crushed stone, assists in unloading hot coke from coke- 
ovens and in delivery to the cars, is used in loading 



272 THE EEIGN OF EUBBER 

steamers with coal or stone, and handles ores of many 
different kinds. 

The service is rough and varied. Thomas Eobins 
writes in ''The India Rubber World" the story of a 
belt salesman who offered his product to a quarry 
superintendent with a guaranty that it would outwear 
any other belt in the market. The superintendent took 
the young man over to the plant where the big crusher 
was at work turning out the two thousand long tons 
an hour. Watching the empty belt, they stood at the 
base of the huge machine. Suddenly the first loaded 
car from the quarry dumped its thirty tons of rock 
with a crash and a roar into the hopper that fed the 
big crusher. The shock and thunder so frightened the 
salesman that he ran away. After he had been 
stopped, his first question to the superintendent was, 
''Where was the accident?" He received the reply, 
"That is an accident which happens one thousand 
times in every twenty-four hours at this plant, and it 
means that this belt which carries away the product of 
the crusher has a practically continuous load of two 
thousand long tons per hour, a large part of it in 
pieces which you could n't lift." 

Metal would wear out and be gone before rubber 
would show serious evidences of wear under these con- 
ditions. As a consequence, for purposes of carrying 
trap-rock and limestone in stone-crushing plants, char- 
coal and ashes in sugar refineries or in concentrating 
plants and mines, earth and stone in large excavations, 
blocks and logs of wood in pulp-mills, clay in brick- 
yards, coal in breakers in connection with large power 
plants and culm piles, tobacco in process of manufac- 




Courtesy of The B. F. Goodrich Co. 

A CONVEYOR BELT IN ACTION 




Courtesy of The B. F. Goodrich Co. 

VULCANIZING A CONVEYOR BELT 



BELTING, PACKING, AND HOSE 273 

ture, customers' packages in large retail stores, grain 
in elevators, mixed goods in coffee-mills, phosphate 
ore in the southern mines, chemical fertilizers in plants 
all over the country, the cotton-rubber conveyor belt 
is essential. For these uses and many others, it has 
come into being and serves with a relatively low cost 
of installation and a cost of maintenance that is un- 
believably smaller than that of any other type of con- 
veyors. Furthermore, it is quiet; and because it is 
uniform in action, it is less wearing upon the motive- 
power. More than twenty- two million dollars' worth 
of belting was sold in this country in 1919. 

Little out-of-the-way things, unheralded and unsung, 
often serve large purposes. The youth who stopped the 
leak in the dike was made famous — a rare accident. 
The inventor of the steam engine, be he Hero or 
Watt, found great difficulty, though, in sealing the 
parts of it from leakage. In fact, in Watt's patent 
of 1769 he states: '' Lastly, instead of using water to 
render the piston or other parts of the engine air or 
steam-tight, I employ oils, wax, resinous bodies, fat of 
animals, quicksilver and other metals in their fluid 
state." Such packing between the cylinder and the 
cylinder-head could not last long. Because boilers, 
pipes, and engines need a little thing, — packing, — ^but 
a stable one, rubber sheeting came to be used. Even 
to lubricate and prevent steam leakage around the, 
piston-rods where they issue from the cylinder, stuffing 
boxes in which packing is used are required. An 
early engineering writer says, "The great desideratum 
in a piston is that it shall admit of no leakage and 
have as little friction as is consistent with this 



274 THE REIGN OF RUBBER 

indepensable quality. ' ^ Watt, the father of the steam 
engine, tried to arrive at these results by the 
use of a metallic packing, but with so little satisfac- 
tion that he gave it up. A number of metal packings 
patented in England before the middle of this century 
were displaced largely by vegetable and animal sub- 
stances, specifically hemp and leather. Engineering 
works of that period show accounts of pistons packed 
with unspun hemp or long rope prepared for the pur- 
pose, kept supplied with tallow by means of a funnel 
on the top of the cylinder lid. 

The employment of cotton and .fiber packing is of 
comparatively recent date. Having engaged, however, 
the ingenuity of some of the best inventors in rubber, 
and possessing a fundamentally sound merit, the use of 
rubber for this purpose has been steady and rapid in 
its increase. The demand for packing has broadened 
until that for piston rods is only one of the many kinds 
produced. Most manufacturers make rubber-sheet 
packing, in the form of cloth insertion and plain pack- 
ing. The advantage in the use of rubber wherever 
steam, air, or water joints are to be made is that no 
other substance which has so much elasticity stands so 
high a degree of heat. No satisfactory substitute can 
be found where the iron surfaces of the joints are 
rough or uneven. Rubber packing made with cloth in- 
sertion is in wide use for steam joints, and the steady 
increase in the yearly production is an evidence of its 
value. 

With the advent of superheated steam, there came 
a demand for packing of special composition that 
would render steam-tight the joints of pipe-lines where 



BELTING, PACKING, AND HOSE 275 

high-temperature and high-pressure steam is used. Al- 
though rubber alone cannot serve here when the steam 
temperature rises as high as 500 deg'rees, a combin- 
ation of rubber and asbestos fibers gradually has taken 
the place of all other sheet packings for use under 
these conditions. Cotton, hemp, and flax do not pos- 
sess great resisting qualities. Asbestos alone has not 
the cohesion necessary, but a combination of rubber of 
proper composition and asbestos as ** superheat pack- 
ing" serves well. This type of packing is, in reality, 
a combination of hard rubber and asbestos — the as- 
bestos to give strength and the rubber to give tight- 
ness. Wherever steam is generated, rubber pack- 
ing is found. Gaskets prevent leakage of air and 
steam. Water pump valves go up and down millions 
of times — some more than thirty millions before they 
die and pass out. 

Hose is the third of our trio. It is a family name 
with many members: fire-hose, water hose, air-drill 
hose, gasolene hose, radiator hose for automobiles, suc- 
tion hose for fire-engines and for drawing water from 
excavations, garden-hose, sand-blast hose, hose for 
chemical fire-extinguishers. Of all sizes, these hose 
vary from an inch long to five hundred feet. One 
of this large family keeps trains running. Like the 
axle-lighting belt, he lives in a poor place under the 
end of a railroad-car. He is married to one on the 
next car to him, although an iron coupling is required 
to keep the twain together. They are out in the 
weather in a swirl of cinders or snow, bending and 
creaking when the car swerves around sharp curves. 
Serve they must at any time, at all times, for through 



276 THE EEIGN OF EUBBER 

them passes the compressed air by which the brakes 
are operated. We call them the air-brake hose. Al- 
though only twenty-two inches long and one and three- 
eighths inches in diameter, they are essential to the 
successful operation of railroad-trains. 

George Westinghouse probably made himself more 
famous by his creation of the automatic air-brake, 
patented in 1872, than by any other one of his many in- 
ventions. The original non-automatic or straight air- 
brake was based upon a very simple steam-actuated air- 
pump on the side of the locomotive. Through the reser- 
voir a pipe-line was carried the length of the train ; and 
even in those days, the connection between the coaches 
was by means of the hose and couplings. This appa- 
ratus was inoperative in emergencies. Westinghouse 
developed the automatic principle in such a way that 
each vehicle carried its own source of power ; and by an 
ingenious valve connection he caused the application 
of the brake whenever there was a reduction of air- 
pressure in the train pipe-line. This has gone through 
numerous improvements and changes since the early 
one; yet the rubber parts to seal properly the 
air in the valve, and the air-brake hose, still constitute 
essentials in this important factor of railroad trans- 
portation. The quality of the hose has been developed 
by cooperative action on the part of rubber manufac- 
turers and the Master Car Builders' Association, so 
that bursting hose is nowadays something almost never 
heard of. 

Several others of the hose family live in the dirt un- 
der the car; they seem to like it. Safety in railroad 
transportation depends heavily upon rubber. An air- 



BELTING, PACKING, AND HOSE 277 

signal hose connects the coaches of a passenger-train, 
and steam-heating hose carries exhaust steam from 
the locomotive to radiators. 

In every passenger coach there are six pieces of 
hose, two of air-brake, two of air-signal, and two of 
steam-heating hose. On the 2,500,000 freight-cars, 
60,000 passenger coaches, and 10,000 Pullman cars, it 
is probable that the air-brake hose equipment in the 
United States includes a matter of 5,000,000 lengths. 
Each of these is replaced about every six months or 
year, because they cannot live long in an atmosphere 
of water, snow, cinders, and dirt. About 10,000,000 
pieces of air-brake hose are necessary every year. 
End to end, these would stretch over 3500 miles — 
enough to reach across the continent. 

Air-brake hose is of uniform size, measuring one and 
three-eighths inches in diameter and each piece being 
twenty-two inches long. It is made of an inner tube, 
several plies of strong, rubberized fabric, and an outer 
rubber cover, all vulcanized together. After this 
process, it is tested to make sure that each piece will 
withstand the suddenly changing air-pressure of about 
125 pounds to the square inch, the bending as the 
trucks go around curves, and the deteriorating action 
of the elements. 

A sum of $26,998,000 was expended for rubber hose 
of all kinds in 1919. 

Were rubber to disappear, the price of copper, ce- 
ment and coal would go up; for in mines delay and 
added expenses would result. The rubber conveyor 
belts, the hose to carry air to the drills that punch 
holes in rock preparatory to blasting, the elevator belts 



278 THE REIGN OF RUBBER 

that carry buckets loaded with acid slimes ; these and 
other rubber articles lead a rough life in the mines and 
smelters. Dragged over rock, submerged in water, 
confined in an atmosphere of fumes, exposed to heat 
and cold, none but the most rugged material can stand 
the abuse ; yet rubber lives and works cheaply. 

In every industry rubber works in diverse ways 
and under varying conditions to serve mankind. The 
paper of which this book is made was, when pulp, held 
in place by rubber deckle straps. It was pressed into 
sheets by rubber-covered couch rolls. 

But in the oil industry rubber is given its severest 
test. Oil attacks rubber ; it is the chief enemy. There- 
fore the chemist has been obliged to mix with rubber 
other substances and in this union to change its 
nature. 

From California to Oklahoma, from Ohio and Ken- 
tucky to Pennsylvania, oil is pumped out of the ground, 
delivered into tanks, passed through great pipe-lines, 
and put on board ship for transport to other countries. 
The big oil companies have tried all kinds of belts 
for driving wells at high speed for twenty-four hours 
a day, both by rotary chisels and percussion. By the 
percussion method a 625-pound bit is lifted and 
dropped into the hole ; in the boring method a one-hun- 
dred-pound bit with a serrated tip is revolved at the 
bpttom of an eight-inch or ten-inch iron pipe. In 
both these methods rubber belting is preferred, be- 
cause it is tough, flexible, cohesive, and has greater 
strength than belting made from any other substance. 
It is water-proof, and it is more oil-proof than other 
materials, although to make rubber oil-resisting is one 



BELTING, PACKING, AND HOSE 279 

of the most difficult problems faced by the rubber 
chemist. Submitting to heavy, uneven shocks, rubber 
belting has a durability that often extends as long as 
five or six years, despite the oil and sand that come in 
contact with it and the rough and careless usage to 
which it is subjected. 

In conveying oil, special grades of oil hose are used ; 
and since these are dragged around a great deal, they 
are frequently protected by metal armor consisting of 
wire wrapped spirally about the length of hose. Some 
of them carry water, some convey air ; but all of them 
come more or less in contact with oil. For conducting 
oil from tanks to barrels, the hose ordinarily has four 
or five plies of frictioned duck, lined with an oil-resist- 
ing rubber compound, and a closely-set, spiral, flat 
wire extending through the core, not only to protect 
the compound from possible corrosion but also to pre- 
vent the hose from kinking or collapsing by reason of 
the vacuum so often employed. To draw oil from stor- 
age tanks of steamships or tank-cars, a suction and 
discharge hose of exceptional strength is employed. 
It must withstand the utmost extremes in weather, the 
harshest handling, and continual contact with rapidly 
moving oil. 

Eubber in the oil-field probably gets its severest test 
in the pumps and the pump packings, which are of va- 
rious sizes, kinds, and shapes. The foregoing enumer- 
ation of rubber needs in oil-fields does not take into 
account the many other articles that are quite indis- 
pensable to handling oil from the time when the heavy 
black fluid is drawn from the depths of the earth to the 
time when, in the form of gasolene and lubricating 



280 THE EEIGN OF RUBBER 

oil, it is delivered to consumers — the tires on the 
trucks, the boots and the shoes, the gloves and the hats, 
the rain-coats used in sunshine as well as in rain. 
Slopping about in sand and water, splashed with oil, 
rubber truly has a hard life in the oil-fields. 

Of the four billion gallons of gasolene used by 
motor-cars each year, all of it flows through rubber 
hose from the filling station to the tank in the car. 
This is a specially made length of hose, the compo- 
sition of which resists gasolene to the maximum. 
Here, if the manufacturer had not been alert, the 
gasolene would swell the rubber and disintegrate it; 
small pieces of rubber would pass into the tjank of 
the motor-car, eventually to clog the needle-valves of 
the carburetor. By joint action between such insti- 
tutions as the Underwriters' Laboratories in Chicago 
and the Rubber Association, special constructions of 
hose have been developed by which the amount of 
action of gasolene upon the rubber has been reduced 
to a minimum. This gasolene hose is usually made 
with a cotton duck lining and a helical flat wire to 
further safeguard the rubber. Outside of this comes 
rubber, then four plies of cotton fabric, and finally a 
spirally wound layer of wire, usually covered by rub- 
ber. Here again one finds flexibility, strength, and 
resistance to corrosion. 

For those who go down to the sea in ships, be it in 
man-of-war, submarine, or passenger transport, rub- 
ber articles do many things. The first and the last 
work in which Charles Goodyear was concerned had to 
do with life-preservers. Even now, though, rubber in 
connection with life-preserves is not used to the ex- 




Courtesy of The B. F. Goodrich Co. 

APPL-flNG RUBBER INSULATION UPON THE BRAIDED JACKET OF GARDEN HOSE 




Courtesy of The B. F. Goodrich Co. 

THE BRAIDING M-iVCHINES MAKING GARDEN HOSE 




Courtesy of The B. F. Goodrich Co. 

VULCANIZING GARDEN HOSE 



BELTING, PACKING, AND HOSE 281 

tent of cork and cotton. It does not age well enough, 
and air-bladders puncture. life-preserving rubber 
suits would be more largely used were they not 
perishable. When the day comes in which all rubber 
articles are as permanent in the air and sunlight as 
wood and steel, then the marked superiority of the 
life-preserver made of rubber and fabric will be recog- 
nized; and ship-owners will use such articles rather 
than the somewhat more permanent but less adapt- 
able cork belt. To provide greater safety in time of 
need to the passengers, is a field in which shipping con- 
cerns should interest themselves. 

The diver depends for his life upon suits of rubber- 
ized fabric, with heavy rubber gloves, with a metal 
headpiece made water-tight by means of rubber gas- 
kets, and, most important, with the hose that go down 
from the pumps, to transmit fresh air and to remove 
exhausted air. 

An ocean-going vessel is much like a small city; 
every phase of human life and every convenience is 
found there. Consequently, if we were to enumerate 
the part which rubber plays in ocean or lake transpor- 
tation, it would be necessary to catalogue the ways in 
which rubber is used in the home, in the office, and in 
the mill and the factory, with, however, the additional 
requirement that on board ship, in the course of 
storms, it is necessary to tighten all openings to keep 
the water out. 

The numerous articles used in the mines, in facto- 
ries, on railroads, and on board ship constitute, broadly 
speaking, what the rubber manufacturer terms 
''mechanical rubber goods." Eubber products are 



282 THE REIGN OF RUBBER 

grouped under the names of clothing, footwear, pneu- 
matic tires, druggists' sundries, and mechanical rub- 
ber goods. Mechanical rubber goods include a vast 
number of products, large and small, the mere enu- 
meration of which would fill volumes; for there are 
probably upwards of 20,000 to 40,000 different articles 
in various sizes, shapes, and colors, and for myriads of 
uses. 



CHAPTER XVIII 
RUBBER IN THE HOME 

A comparison between the American bath-room and 
the English one, reveals some interesting differences. 
In England one may not find a rubber hot-water bottle 
hanging behind the door, but he is likely to find a stone 
or metal one under the wash-basin. Of late years, the 
English bath-room has achieved a rubber sponge, some- 
times a solid rubber shaving-dish, and a rubber bath- 
plug to keep the water from running out of the bath- 
tub. In American homes, however, rubber has worked 
its way into a large variety of convenient uses. The 
hot-water bottle is one of the basic necessities. Then 
there are fountain syringes, rubber bath-mats, rubber 
soap-dishes, rubber aprons, rubber sponges, women's 
bathing caps, the tooth-brush with its hard rubber to 
keep the bristles from coming out, hand brushes, nail 
brushes, shower attachments, and, in the spring when 
colds are prevalent, the rubber bulb and tube connected 
to the nasal spray outfit. We surely depend upon rub- 
ber in the American bath-room and medicine-cabinet. 

The American loves his bath-room, whether it has 
tub or shower. But he does not want the water to run 
all the time. It leaks too much from bib and faucet 
as it is. By a soft rubber disk pressing against metal 
when the wheel is turned, the water is shut off. If our 
plumbers would use high-grade rubber mixtures for 

283 



284 THE EEIGN OF EUBBER 

these disks, there would be less trouble in the house- 
hold ; too many of them contain no rubber at all, being 
merely paper, which soaks up water and wears out 
rapidly. 

I am afraid this chapter will read too much like an 
advertising man's copy, with rubber, rubber every- 
where. But we do live in the reign of a rubber de- 
mocracy in which there are many members. Not the 
least of them is the gentle lord of the bath — the rubber 
sponge. Purity and cleanliness characterize this in- 
timate individual. Usually, it is formed of a large 
proportion of rubber, with considerable oil to make it 
soft and flexible. With this is mixed sulphur in the 
finest form. To attain such fineness the sulphur is 
made by chemical precipitation with the vulcanizing 
ingredient, antimony sulphide, a mild accelerator. In- 
corporated with these is some substance like ammo- 
nium carbonate, which, upon heating, produces a gas. 
This rubber mixture is not mixed in the usual way, 
but so as to be soft and uniform. Unless plasticity 
is attained, the rubber will not ''blow," as we say. 
After pieces of the mixture are put inside hollow iron 
molds, heat is applied only at the temperature at which 
gas is given off from ammonium carbonate. The soft 
plastic mixture, by reason of the gas, rises like bread, 
blowing up into bubbles with little membranes of rub- 
ber between them. Finally, as the process goes on, the 
entire cavity of the mold is filled with the porous mass. 
The heat is then increased up to the vulcanizing tem- 
perature, and kept there until the rubber is completely 
vulcanized. After cooling the mold is opened, and the 
sponge, in somewhat rough form, is removed. By a 



EUBBER IN THE HOME 285 

simple device the outside skin is cut off, and the sponge 
as we buy it in the drug store is ready. 

But the flowers, garden, and lawn need their shower- 
baths as much as do we, to keep" their vitality during 
the summer's heat. Rubber garden-hose is their true 
friend. Out on the golf course night after night a 
little twinkling light may be seen, flitting from green 
to green. The spooks might be playing golf, but 
it is not they, nor is a duffer player practicing putts. 
Most of us putt in the dark on Saturday afternoons. 
No, in this case the greens man waters his greens by 
night with length after length of rubber garden-hose 
to convey the water needed for the growth of the deli- 
cate bent and fescue grasses. Players are exacting; 
each square inch of green must needs be covered evenly 
with fine blades of special grass. We cannot drag 
iron jpipe over greens to tear and roughen them. 
Thus, rubber garden-hose serves the golfer as well 
as the gardener. Probably two thousand miles of 
garden-hose are made in the United States every 
month. 

Garden-hose is constructed of several essential 
parts : an inner tube heavy enough and uniform enough 
to retain water and not to deteriorate on standing; a 
cotton fabric or cord body of several plies, between 
each pair of which is a rubber layer to stick the cotton 
together ; finally, an outside rubber cover, thick enough 
to withstand tearing as the hose is pulled over the lawn 
and the sidewalks. It is probably the one article that is 
handled by the user with the least consideration. Who 
of us picks it up carefully and carries it out to the 
front lawn? We grab one end and drag it. We kink 



286 THE EEIGN OF EUBBER 

it in several places; we haul it over the sidewalk; we 
jerk it and pull it if the coupling happens to catch. "We 
give it every possible abuse. It is out in the weather 
constantly; and when the cover or tube is punctured, 
the fabric decays in contact with water. 

The rubber mixtures for tube, insulation, or cover — 
and they do not differ greatly in composition— are 
taken after mixing into the hose manufacturing depart- 
ment. Here the first operation is to form the tube of 
the hose by squeezing the compound through the die of 
a tubing machine, as previously described. Before the 
rubber is fed into the tubing-machine, an operator 
softens the compound, or, as he calls it, the ''stock." 
He then cuts it into strips and passes it to another 
man, who operates the machine. The second operator 
feeds this warm, soft stock into the cylinder at the feed 
end, another man watching the issuance of the long, 
hollow tube and seeing that it is carefully wound up 
upon a large reel or drum. The composition must be 
stiff enough not to collapse ; and to prevent its sticking 
together in any place, a little soap stone is fed into it 
through a special attachment in the die. Mean- 
while, a slight air pressure is maintained inside 
this tube to keep it in shape. When about five 
hundred feet of it are wound upon the reel, it is rolled 
to the braiding-machine. After the tube is rounded out 
by just enough air-pressure to give it shape, it is au- 
tomatically fed to the center of the braiding-machine. 
This is a noisy instrument, like all cotton machinery. 
Little spools containing cotton cord are forced by the 
mechanism in and out and around each other in such 
a way that, as the rubber tube passes up through the 



RUBBER IN THE HOME 287 

machine, it is surrounded by interbraided cotton cords 
spirally and continuously woven. 

Some garden-hose is made on the plan of the cotton, 
rubber-lined fire-hose, but in the type we are describ- 
ing one ply or layer of cotton cord is not sufficient to 
give strength and durability ; therefore, when this reel 
of unvulcanized hose is covered with its layer of cord, 
it is taken back to the tubing-machine again. But how 
shall a partly made hose be covered with rubber? We 
certainly cannot pass the hose through the cylinder of 
the machine and through a die, for that would simply 
grind it up, cotton and all. Here a leaf is taken out 
of the book of the insulated wire manufacturers. 
Upon this particular tubing-machine is an insulating 
head; that is, a piece of metal with holes properly 
arranged in it is so placed on the head of the tubing- 
machine that the entire hose may pass through a cav- 
ity running at right angles to the direction of the flow 
of the rubber. As the hose passes through this cavity, 
the tubing-machine forces soft, unvulcanized rubber 
around it. By an ingenious device the die of this in- 
sulating head permits only a certain thickness of rub- 
ber in the form of a continuous tube to be laid on the 
surface of the cotton. Thus, our rubber hose now 
issues from this operation with a thin layer of rubber 
on top of the cotton layer. After the reel is filled again 
with five hundred feet or more of insulated hose, it is 
taken back to the braiding-machine. Once more the 
little spools run around each other, and a second ply or 
layer of cotton cord is wound upon the partly manu- 
factured hose. 

Still the hose is not complete ; for certain uses, three 



288 THE EEIGN OF EUBBER 

or even four plies of cord are necessary. We shall 
assume, however, that three plies are required. The 
hose, after the application of its second layer of cord, 
goes back to the insulating head of the tubing-machine, 
through which it again passes and adds another layer 
of rubber. Then back it goes to the braiding-machine, 
where the third layer of interlocked, woven cotton cord 
is applied. So far as strength is concerned, we should 
need to add no more rubber to this hose, with its tube, 
its three plies of cotton, and its two layers of rubber 
between them. But we know that it will be dragged 
about on the ground and in the water; we know also 
that water causes deterioration of cotton, for wet cot- 
ton mildews and decays rapidly. Therefore a protect- 
ing layer of rubber must be applied outside this last 
layer of cotton. Back again goes the almost completed 
hose to the tubing-machine, where it passes through 
the insulating head and die. In this case, however, 
there is applied a somewhat thicker layer of rubber 
of a different mixture, a tougher one, designed to re- 
sist the wear and tear on the ground. 

These operations have produced five hundred feet 
of garden-hose, blown up with a few pounds of air- 
pressure to keep it fully rounded. Wound up on a 
reel, the layers separated by paper or varnished cloth, 
the hose, on a factory type of small wheel truck, is 
pushed into another room. Here several of these reels 
are gathered together at one end of a long vulcanizing 
press, for the hose is to be vulcanized at the rate of 
about twenty feet at a time. To accomplish this, two 
heavy steel plates have been made, each of them 




Courtesy of The Boston Woven Hose and Rubber Company 

FORCING THE JAR RING COMPOUND THROUGH A TUBING MACHINE 




Courtesy of The Boston Woven Hose and Rubber Company 

CUTTING JAR RINGS FROM THE VULCANIZED TUBE 



RUBBER IN THE HOME 289 

grooved full length. When these two plates are 
brought together, there is a circular opening through 
their length of the exact diameter desired as the out- 
side diameter of the hose. One of these plates is 
bolted to the top of the press, and the other is bolted 
to the movable part. Each plate contains six to ten 
of these semicircular grooves. The operator draws 
into the grooves a length of hose from different reels 
sufficient to fill them from end to end. Then the lower 
half is pushed up by hydraulic pressure against the up- 
per half, thereby confining the hose in the tubular open- 
ings formed by bringing together the two sets of 
grooves. The hose is in contact with the hot plates or 
molds long enough to vulcanize the composition. The 
plates are then separated, and the hose is pulled 
through to bring another length in contact with the 
mold. Again the molds are closed and heated. Thus, 
twenty feet or more at a time, the hose is vulcanized 
from end to end. When it is inspected and the rough 
ends cut off, finally it is rolled upon a wooden packing 
reel, ready for shipment. There are other methods of 
making garden-hose, but this is probably the simplest 
of them all. 

There are many different kinds of hose, not the least 
important of which is that for conducting solutions of 
chemicals used in spraying orchards. Fruit would be 
poor indeed were insects not killed by chemicals applied 
by orchard sprayers, with their rubber hose connec- 
tions of special sizes, lengths, and types. The little 
bucket-spray pumps with four- or five-foot lengths 
of three-eighths-inch spray hose, the large horse-drawn, 



290 THE EEIGN OF RUBBER 

and the gasolene-power types, all have hose connecting 
them and permitting the operator to move about and 
thoroughly spray his orchard. Sprayers of the power 
type usually develop pressure from 250 to 300 pounds 
to the square inch. The fabric construction of the 
spray hose must be made to withstand these pressures. 
Furthermore, since spraying liquids are composed of 
different chemicals, the lining of this spray hose must 
be made of most carefully constructed rubber mixture. 
The problem is not wholly one of pure rubber; it is 
a question of mixing with pure rubber those ingredi- 
ents which give toughness and strength to the composi- 
tion, and an ability to withstand the action of the chem- 
icals. This condition is somewhat difficult to attain in 
rubber, particularly when emulsion sprays containing 
oil are used. Rubber absorbs oils with great rapidity ; 
it swells, softens, weakens, and deteriorates under 
their action. Therefore, he who sprays his orchards 
would be wise if, after each operation, he were to pass 
through the hose a sufficient quantity of water to wash 
out the chemicals and thus minimize the action of them 
in the deterioration of the rubber. 

Another of the necessary uses of rubber in modern 
days is in the home canning of fruits and vegetables. 
We think of the process as new, but in 1795 a method 
was invented by a Frenchman, Appert, for preserving 
foods in hermetically sealed receptacles. He was 
awarded a prize of sixteen thousand francs by the 
French Government. His process consisted in placing 
the articles to be preserved in cork receptacles and 
subjecting them to the heat of boiling water for various 
lengths of time, depending upon the nature of the 
foods. Although Appert 's process was kept secret for 



RUBBEE IN THE HOME 291 

some time, it gradually leaked out; in 1815 it was 
brought from England to America. In 1819 an Eng- 
lishman named Daggett had a canning factory in New 
York City for packing lobsters, salmon, and oysters; 
and in 1825 fruits and vegetables were canned. At 
this time only glass jars were used; but the cost and 
frequent breakage led to the use of tins, the first pat- 
ents for which were secured in England in 1823 and in 
America in 1825. Because sterilization by boiling in 
water w^s found to be insufficient for many products, 
salt was added to the water to raise the boiling-point. 
In 1874 a Baltimore man invented a closed retort for 
cooking with superheated steam. From this came 
our modern steam-pressure devices, which produce 
various temperatures above 212° Fahrenheit. 

The canning industry has become extensive. The 
figures amaze one. The National Canners' Associa- 
tion reports that in 1919 there were packed in the 
United States more than 1,385,000,000 cans of vege- 
tables, more than 634,000,000 cans of fruits, and more 
than 716,000,000 cans of fish and oysters. These make 
a total of more than 2,736,000,000 cans ''put up" in 
one year. And the home is not heard from in these 
records. 

Without entering into the principles of hot canning, 
we should note one fact as fundamental ; the cans must 
so be sealed as to prevent any ingress of air. Among 
the many substances used for this purpose, the chief 
of them is rubber ; even the tin can usually has a little 
rubber seal between the sides and the base. Because 
it is odorless and tasteless, because it is resistant to 
the action of fruit acids, because bacteria cannot grow 



292 THE EEIGN OF EUBBER 

in it, rubber has become one of the most necessary 
links in this chain of important operations, the end of 
which is the preservation of food in palatable, health- 
ful, usable condition. Before canning, all the fruits 
and vegetables are picked over in the factory, just as 
our cooks do in the kitchen. Girls with carefully ster- 
ilized and manicured hands sit before a long table upon 
which slowly moves a sanitary rubber conveyor belt, 
usually white in color, which carries the fruit to be 
sorted. 

In the home, large quantities of fruit and vegetables 
are preserved each year in glass jars. This process 
is more economical than the use of tin, because the jars 
can be used repeatedly. The glass top, however, must 
be air-tight; and for this purpose, ever since home 
canning began, the rubber ring, known generally as 
the *'jar ring," has been used. The jar ring is busily 
engaged in filling its mission in the twenty-four mil- 
lion homes in our country during the canning season. 
One rubber company alone informs me that it makes 
every hour during the winter enough rubber jar rings 
of one brand alone to make a pile, one on another, as 
high as the Woolworth Building ; and their production 
for a year of this particular brand would, if linked in 
the form of a chain, go around the world three times. 

In the process of making jar rings the first essential 
is the choice of a rubber composition. This composi- 
tion must have certain properties: it may contain no 
substances that can be absorbed into the acid liquids 
and give either taste, odor, or poison to the preserves. 
After it is mixed in the usual way this rubber com- 
pound is manufactured by a very simple process. It 



EUBBER IN THE HOME 293 

is taken from the central mixing-room to the jar ring 
factory, where it is warmed on a warming-mill and 
forced through a large die in the head of a tubing-ma- 
chine, much in the same fashion as garden-hose. Gar- 
den-hose tubes are small, but the tube from which the 
jar ring is cut is large in size and thick in wall. The 
thickness of the wall is that of the width of the thin 
section of the ring as the consumer obtains it. 

As the tube comes from the machine, it is cut into 
short pieces, usually about three feet long. An opera- 
tor places the tube upon a mandrel or iron pipe. Then 
a large number of these mandrels are put into a vul- 
canizer containing water; and the vulcanizing is done 
by heating this water to the proper temperature and 
maintaining in the water, usually, a slow but regular 
circulation. When this heavy tube is vulcanized, it is 
removed to a jar ring cutting machine. Here the 
workman has but to remove the tube from the mandrel 
and place it upon a cutting mandrel, and the machine 
does the rest ; that is to say, a sharp knife runs in and 
out, cutting the rings automatically at the rate of fifty 
thousand an hour. After they are cut, they are care- 
fully inspected by expert girls, counted, and packed in 
the boxes in which they are sold. 

As I write, the canning season in my home has just 
begun. Strawberries are coming in from the garden ; 
soon it will be currants, raspberries, and later, peaches. 
For several weeks the kitchen will be redolent 
of sweet smells, but mere man must stay out of the 
bustle and boiling. Whether hot pack or cold is being 
used, as a rubber man, I look after the jar ring pur- 
chases, to see that they are of proper quality. I de- 



294 THE EEIGN OF EUBBER 

mand good quality ; the rings must be strong enough to 
stretch around the top of a Mason jar and not so soft 
that they will squeeze out and leave places for air and 
fungi to creep in and spoil the fruit, if I am to pur- 
chase them. 

All rubber men like fruit in the winter, I imagine. 
Perhaps for this reason, as well as from a sense of 
responsibility for the needs of the householder, they 
got together some years ago and, with the cooperation 
of the Bureau of Standards, developed for the Depart- 
ment of Agriculture, that loyal agent of the house- 
wife, a specification according to which jar rings 
should be made. Eresponsible manufacturers take 
pains to see that these specifications are carried out. 
It is simple for you to test jar rings in accordance with 
the Farmers' Bulletin No. 1211 of the United States 
Department of Agriculture, ''The Home Canning of 
Fruits and Vegetables." The tests, if followed, 
will show you whether the jar ring will sustain 
a load of seventeen pounds before breaking, and 
whether it is flexible enough to stretch from four inches 
up to ten inches without breaking. These two tests 
of strength and stretch are the fundamental ones 
indicating a good rubber composition. For use 
in the hot pack method it is advisable to test the ring 
in boiling water. In position on a jar and placed 
in boiling water for four hours, it should not, 
after cooling, be swollen or show signs of cracks or 
cuts resulting from pressure. 

If your home happens to be on the farm, you prob- 
ably sell milk. The old-fashioned method of milking 
by hand is gradually giving way in the larger dairies 



I 



RUBBER IN THE HOME 295 

to newer methods of milking by machinery. Conserva- 
tive as we may be, and desirous of holding to the old 
and not taking on the new, yet demands for sterile, 
clean milk have grown to be so heavy that every pos- 
sible method to prevent contamination by dirt or bac- 
teria must be adopted. Therefore the milking-ma- 
chine is coming more and more into use. 

There are many different types of milking-machines. 
The experimental work leading to their development 
began probably as far back as 1819, but modern de- 
velopment began about 1878. There have been three 
different principles. The milk-tube idea, providing 
for an opening into the milk cistern and allowing the 
milk to flow from the udder, is dangerous and is not 
used. The second method adopted the pressure prin- 
ciple. The third method, which has come into extensive 
use, places the teat into cups from which the air is ex- 
hausted, the exhaustion producing a vacuum in the 
manner produced by a calf when suckhng. There have 
been different patents, but the fundamental principle 
consists of a vacuum pump or ''pulsator." To this 
pulsator are attached two lengths of rubber hose and 
a specially designed connection for teat cups and teat- 
cup mouthpieces. Thus a pulsating vacuum is ap- 
plied to the teat, bringing its flow of milk into the vac- 
uum milk-pail. 

The particular rubber parts which make this milk- 
ing-machine possible are the teat cups, the rubber 
tubes that convey the milk into the pails, and the rub- 
ber hose that permits a vacuum to be applied to the 
milk-collecting pails. These cups are made of purest 
rubber, soft, flexible, and permanent. 



296 THE REIGN OF RUBBER 

All things that come in contact with milk must be 
kept clean. To enjoy good milk, one must keep the rub- 
ber parts just as clean and sterile as the pails and cans. 
Those who use milking-machinery should be careful 
to see that the directions of the milking-machine com- 
panies are carried out. The rubber parts should be 
washed and carefully sterilized ; and between the times 
that the machine is used, they should be kept immersed 
in plain boiled water. The rubber tubing and cups 
should never be allowed to become dry. To sterilize 
them, the College of Agriculture at Cornell Uni- 
versity recommends a solution of water containing 
salt and chloride of lime. It is well to remember that 
the fats of milk are readily absorbed by rubber; if, 
therefore, the rubber parts are not washed after each 
milking and kept in sterilized water, more and more 
butter fat will be absorbed into the rubber, with conse- 
quent deterioration. The secret of keeping the rubber- 
ware sweet is always to store it wet with clean water 
and never to let it come in contact with oils or fats, for 
they swell and weaken rubber. 

Within the limits of our space, all the articles of rub- 
ber found in the home could scarcely be described. 
They are too numerous, although different enough to 
warrant separate treatment. For comfort on cold 
nights millions of hot-water bottles are in use. They 
are made from sheeted rubber, colored, adorned with 
configurations on the surface, to be agreeable in ap- 
pearance. Girls build them into shape, or men moid 
them in steel molds under pressure. Only the clean- 
est rubber and the most dirt-free processes are em- 
ployed, for the bottle must not leak. 



RUBBER IN THE HOME 297 

Even straw and felt hats, awaiting tlie call to adorn 
the head, have been helped by rubber forms upon which 
they were pressed in the making, and in so intimate 
an article as the garter and the *' braces" of the Eng- 
lishman we depend upon rubber thread, while rub- 
ber has come to replace leather in the belts preferred 
by American men. 

But it is in relief from the burdens of housework 
that rubber serves as a real aid to the housewife, in 
city or country. Sweeping and dusting are made easier 
by rubber-wired and rubber-tired vacuum and carpet 
sweepers. To the sewing-machine electricity is con- 
ducted by rubber-covered wire. But best of all is 
the routing of blue Monday wash-day. The laundry 
in recent years has changed from a back-breaking 
place, dreaded each week, to a light, happy room. 
Equipped with motor-driven washing-machine and rub- 
ber wringer rolls, with soft, warm rubber mats and 
with electrically heated mangle, this part of the home 
has become a scene of happiness. 

Rubber in the home is a dependable commodity. It 
is gentle, noiseless, — a good servant. 



CHAPTER XIX 
GAS-MASKS 

One fine afternoon in May, 1917, a telegram came to 
my office from Washington, which stated that Profes- 
sor Gibbs of the Bureau of Mines would come to see 
me on an important matter connected with the war. 
The following morning he arrived and showed me a 
gas-mask of the box-respirator type that had been 
made by the English. He asked if it could be dupli- 
cated easily. There was very little gas-mask infor- 
mation in the United States at that time. The first 
mask brought to this country from the front was of 
German make. This type seemed to fit the needs of 
the Navy Department, and a small order had been 
placed with the rubber companies. After the usual 
difficulties incident to a new article, we had duplicated 
the German construction as closely as possible. Little 
was known over here at that time of the type of chem- 
icals used for gases; else I am sure a considerably 
different type of rubber material would have been em- 
ployed in making these first gas masks. 

On Wednesday of that week, Bradley Dewey came 
into my office, after having been heralded in advance 
by a telegram from Washington. His first remarks 
were, as always, straight to the point. "We want 
you," he said, *Ho make the rubber parts for 25,000 

298 



GAS-MASKS 299 

gas masks by ten days from to-day/' He was nothing 
if not direct. We told him that he might as well ask 
us to move the building in which we were sitting to 
Brooklyn in ten days. Such a retort made no impres- 
sion; he went right on: "I am not yet commissioned; 
I have no formal order to give you. You will have to 
run your chances of getting your money back ; but we 
want the masks, and we are going to have them. ' ' He 
gave no reasons for his statements ; but we sensed one 
and thought at once, as it subsequently developed, that 
probably a force of American soldiers was to go over- 
seas immediately and needed full equipment. It was 
of no special credit to the B. F. Goodrich Co., that we 
accepted the call. AU American business men did the 
same in those days. 

Because of the method of de-sign, it would have been 
impossible to create an exact duplicate of the English 
mask in so short a time. Short cuts, modifications to 
permit speed of production, were necessary. The 
technical staff, officials, and Bradley Dewey sat down 
together and worked out the program. By 'Saturday 
there were thirteen machine-shops making the metal 
forms and molds. They jumped in to help, as did 
thousands of little shops in this country, whose names 
are unknown but which were keystones in the arches 
of the war machine. By Monday the regular peace- 
time occupations of two departments of the factory had 
been abandoned, and in place of them various gas-mask 
parts were in process of manufacture. By Wednesday 
we were making more than three thousand masks a 
day ; and at the end of the ten days we had nearly com- 
pleted the order. These were not good masks; but 



300 THE EEIGN OF RUBBER 

they did have a definite value in offering some pro- 
tection against gas. 

More than all else, however, this initial attempt 
taught us many things regarding the size and details 
of the gas defense problem. As Crowell and Wilson 
say in their ''Armies of Industry": **To produce 
25,000 gas-masks in three weeks meant to compress 
England^s two years of experience into twenty-one 
days. The military authorities at that time could 
plead entire ignorance of the qualifications of an effi- 
cient gas-mask. The prevailing idea seemed to be that 
you could go out into the market and buy them by 
the hundreds of thousands as you could buy Hallowe'en 
masks. ' ' 

More information filtering through to us from 
abroad during June, we came to realize — manufac- 
turers, and War Department — that this was no ordi- 
ary war and that protection against the highly com- 
plex and constantly changed poisonous gases was a 
matter that would require research work of the first 
magnitude and cooperation of the highest degree. 
For this purpose the Gas Defense Division of the 
War Service Committee of the Rubber Association 
was organized to coordinate with the War Department. 
To their lasting credit, be it said that always the army 
officers were pleasant, courteous, progressive, and fair. 
The committee and the officers together wrote specifi- 
cations according to which the manufacturers produced 
the masks. They made them severe in order to insure 
to the soldier a resistant, durable protection. 

To comprehend gas-masks, one should understand a 
little of gas warfare. Gas is the most treacherous 



I 



GAS-MASKS 301 

of all the weapons of offense, for it may be something 
like the ancient Greek, Pelopidas, who, so Plutarch 
states, on hearing the remark of a soldier, "We are 
fallen among enemies," replied, ''How are we fallen 
among them more than they among us?" In its use, 
the wind may change and blow the gas back to the 
place whence it was sent. Poison gases were first used 
in warfare between 431 and 404 b. c, when the Athe- 
nians and Spartans, in the southern part of Greece, 
besieged certain cities. In doing this, they tried to 
overcome their opponents by the use of burning sul- 
phur, which produced fumes irritating to the eyes and 
throat. While we may look back to ancient Greece 
with awe and admiration for wonders of art and liter- 
ature, we must give them the discredit of having insti- 
gated the use of chemicals in the attempt to outdo 
their enemies. 

Despite international prohibitions, Germany had 
planned the use of noxious chemicals before the war 
broke out. Ludendorff states in his ' * War Memories ' ' 
that the Germans used gas shells against the Russians 
on January 31, 1915. Gourko, the Russian, writes 
that at about the end of December, 1914, the Germans 
introduced shells charged with asphyxiating gases. 

Regardless of these early preparations of the Ger- 
mans, the English and French were taken completely 
by surprise in April, 1915. Because something had to 
be done and quickly. Lord Kitchener appealed to the 
women of England, by whom the first mask was made, 
which was not a mask at all. It was merely a series 
of cheese-cloth pads soaked in chemicals. 

The French studied protective devices. The first 



302 THE REIGN OF RUBBER 

French masks were also pads impregnated with 
chemicals. The chemicals were repeatedly changed, 
and glasses for the protection of the eyes were intro- 
duced. By the end of October of that year the French 
had developed an apparatus called the M-2 mask, which 
consisted of a series of fairly loosely fitting gas pads, 
with permanent eye-pieces of cellophane. In this, as 
in the earlier ones, air was breathed in and out through 
impregnated cloth. 

The English had been at work in the same general 
way; and during the same year they had developed 
what was known as the PH helmet, a heavy cloth hood 
containing eye-pieces. The hood went over the head, 
the air coming through the cloth impregnated with 
chemicals to absorb the gases, and the exhalation pas- 
sing out through a special rubber valve known as a 
flutter-valve. The difficulty of breathing through these 
contrivances was serious. Nor was protection com- 
plete. It jbecame necessary rapidly to develop appa- 
ratus that a soldier could wear with a reasonable de- 
gree of comfort and by means of which he could live 
in an atmosphere of high gas concentration. The 
French organized commissions for chemical investi- 
gation in 1915. The English, under the leadership of 
the late Lieutenant-Colonel E. F. Harrison, C. M. G., 
were organized likewise; as a result of this organ- 
ization the English box respirator was developed. 
Colonel Harrison prepared the manufacture of the 
respirator on a large scale; and it is a great testi- 
monial to his foresight and energy that despite all 
the difficulties of production, the supplies promised to 
France never failed. 



GAS-MASKS 303 

The gas-mask is not wholly a matter of rubber. It 
comprises four parts: first, the rubber face-piece, in- 
cluding eye-piece, inhalation tube, and rubber exha- 
lation valve; second, the flexible rubber hose; third, 
the canister containing chemicals; fourth, the canvas 
knapsack or carrying-case. The purpose of a gas- 
mask is to protect the eyes from the irritating effects 
of gases and to filter them from the air through a series 
of layers of absorbing chemicals in a canister. The 
exhaled' air is forced out through a separate valve, 
to prevent it from vitiating the chemicals. 

Making such an apparatus was a complicated prob- 
lem, involving a knowledge of the intricacies of chem- 
istry, physiology, rubber, and, not the least, the tem- 
perament of the soldier. The canisters were required 
to exclude smoke, suffocating gases, tear-gases, sneeze 
gases, nauseating gases, and the more virulently toxic 
gases. As a chain is no stronger than its weakest link, 
the canister for filtering the chemicals from the air 
would be of little consequence if contaminated air 
leaked in around the edge of the mask because of faulty 
design or through an easily penetrable material. All 
sorts of substances for face-piece construction were 
tried; yet only vulcanized rubber seemed to combine 
strength, durability, and a reasonable degree of im- 
penetrability. 

The flexible rubber hose was a problem of its own. 
A rubber composition free from porosity was mixed. 
Covered with a flexible cloth known as stockinette, 
the rubber was molded to be light, strong, and flexible. 
The exhalation valve or flutter-valve, through which 
the expired air passed, consisted essentially of two 



304 THE EEIGN OF EUBBEE 

flat pieces of rubber vulcanized together on the edges. 
When air was breathed out of it, it opened easily ; but 
it shut itself tight at each inhalation. 

The face-piece of the English box respirator was 
made of a thin cotton fabric dyed olive drab, upon 
which was applied a smooth layer of rubber vulcan- 
ized in hot air. It was secured upon the head 
by means of tape and elastic bands. In order 
that there might be no breathing through the nose, a 
nose-clip with rubber ends was used, the force of wire 
springs keeping the nose shut. The breathing, there- 
fore, was done through the mouth, into which fitted 
a special mouthpiece of rubber upon which the teeth 
could close. A rubber flange that lay between the 
teeth and the lips prevented the soldier from breathing 
any bad air that might be inside the face-piece, when 
he opened his lips under severe exertion. This ar- 
rangement gave to the mask what was called the double 
line of protection. 

There were serious objections to the mask. Per- 
spiration from the face rapidly condensed upon the 
eye-pieces, so that vision was seriously interfered 
with. The nose-clip, the mouthpiece, and the lack of 
ventilation within the face-piece chamber produced ex- 
treme discomfort. 

To overcome these difficulties, particularly that of 
the fogging of the eye-piece, Dr. Tissot, a Frenchman, 
in 1916 invented a mask that consisted of a metal box 
carried on the back, containing the absorbent mate- 
rials, through the lower part of which the air came 
in, and out of the upper part of which the flexible tube 
passed over the shoulder to the mask inlet. The face- 





THE ENGLISH PH HELMET 



THE AKRON-TISSOT GAS MASK. THE IQI? 
MODEL 




lurtesy of Chemical Warfare Service, 
U. S. Army 

THE I919 MODEL GAS MASK 



MEN IN FULL MASK AND PROTECTIVE 
CLOTHING 



GAS-MASKS 305 

piece was made of almost pure gum rubber. To 
avoid the dimming of the eye-pieces, little tubes were 
run up to them from the inlet, so that all the air 
breathed in was swept over the inside of the eye-pieces, 
and prevented moisture from condensing upon them. 
This Tissot mask was used for artillerymen, observers, 
and sappers. When it first came to America, the idea 
stimulated development for the infantry. Because 
the face-piece was tight and comfortable, because the 
eye-pieces did not become dimmed, because there was 
nothing in the soldier's mouth to prevent his talking 
and to compel salivation, this mask was more comfort- 
able than any previously developed apparatus. The 
rubber was thin and of great flexibility, but lacked 
durability. 

To perfect such a comfortable mask required con- 
stant tests and studies. It had to fit the face perfectly, 
leakage around the edges having been observed in 
testing-chambers built for that purpose by the Chem- 
ical Warfare Service. By going into these chambers 
in the presence of different gases and under different 
concentrations men tested leakage. The ''poison 
squads ' ' were always at work. The physiologists and 
the psychologists studied the best shape of masks. It 
was necessary for them to fit into the hollows of the 
temples and give the jaws free space in which to work, 
yet not press back against the Adam's apple. The 
early masks were a joy to the fat man, but a. terror to 
one with a cavernous face. With the pressure of the 
mask on the forehead carefully determined, the line 
of pull of the attaching bands was regulated so that 
pressure upon the supra-orbital nerves, just above the 



306 THE EEIGN OF EUBBER 

eyebrows, became so small that the discomfort from 
it was reduced to a minimum. 

To fit all sizes of faces and heads was a problem. 
Equipped with regular as well as experimental masks, 
men of the Field Testing Section of the Gas Defense 
Division were constantly in and out of gas. They 
played base-ball in masks, dug trenches, laid out wire, 
cut wire, and fought sham battles at night, both with 
and without actual gas. Without ill effects, men 
worked, played, and slept in the masks for a week at 
a time, only taking them off for thirty minutes to eat, 
and each day entering high concentrations of deadly 
gases. 

The dream of the gas-mask designer was to create 
one that could be worn constantly, and to this end 
the greatest efforts of rubber men and army officers 
were devoted. The first step toward this ideal 
was a modification of the French Tissot, which came to 
be known as the AT or Akron-Tissot mask. The face- 
piece was made of the cloth known as stockinette, un- 
der which was a layer of rubber, the whole being vul- 
canized on a form the size and shape of the face. An 
attempt to build a mask to fit a face, just as a rubber 
shoe is built to fit a foot, was made by cooperation 
between the Chemical Warfare Service and the Rub- 
ber Association. In order to keep the eye-pieces 
free from moisture, a specially formed rubber tube was 
made to fit upon a peculiar, snout-shaped, metal nose- 
piece. This rubber tube was of a Y-shape, laid inside 
the mask, in distinction from the French Tissot. 
Therefore, the incoming air went through these tubes 



GAS-MASKS 307 

and swept over the eye-pieces. Cotton webbing con- 
taining rubber thread was attached at the proper 
places to hold the face-piece in contact with the head. 
Although still not quite thick enough to withstand 
gases for the maximum time, these masks gave an 
excellent account of themselves. Another type was 
known as the KT mask. 

I have made little mention of the other rubber parts 
of the mask. The face-piece, the flutter-valve, the 
head-bands, and the flexible hose all are made of rub- 
ber to a greater or less degree. There is also a neces- 
sary little rubber valve, about which no one has said 
much, on the inlet side of the canister. This valve 
has the duty of closing on exhalation and opening on 
inhalation, so that it acts exactly in the reverse way 
from the flutter-valve. If it ever fails to act, some 
of the air passes back through the canister and de- 
creases the absorbing power of the chemicals. 

At Long Island City was built a large gas-mask fac- 
tory with technical laboratories where ideas were 
worked out in a spirit of cooperation and earnestness 
to produce the best possible gas defense equipment for 
the American soldier. The speed with which the or- 
ganization was brought together and harmonized and 
production accomplished will ever stand as a monu- 
ment to the Chemical Warfare Service. It brought 
together and combined the ideas of those who had been 
overseas and those connected with rubber, with the 
result of field tests. Cooperation was the watchword, 
a real part of which was with the liaison officers from 
England and France. Those who came to know Major 



308 THE EEIGN OF EUBBER 

Dudley appreciated the spirit of the English. His 
keen knowledge, his quiet yet forceful manner, stimu- 
lated us to greater eifforts. 

Just at the close of the war, before all gas-mask 
work was transferred to the Edgewood Arsenal and 
these wonderful laboratories and factories closed, the 
latest type of mask, known as the 1919 Model, was de- 
signed and put into production. It has been described 
admirably in some detail in Fries and West's recent 
work ^'Chemical Warfare. '^ It was capable of high- 
speed production ; the face-piece was made of heavier 
rubber, so that the resistance to penetration of gases 
was much greater ; the attachments and the head-bands 
were scientifically worked out to give the minimum 
tightness upon the head, with a maximum freedom 
from leaks at the temples ; the eye-pieces contained tri- 
plex glass, so that danger from breakage injury was 
reduced to a minimum. The incoming air was thrown 
upward and over the eye-pieces, keeping them clear no 
matter how much the exertion or what the tempera- 
ture, except in rare cases when the thermometer was 
below zero. The fitting of the mask in its knapsack 
was made more convenient than in any other type, 
with the result that the soldier could get the mask on 
his face more rapidly. The canister was literally a 
work of art as well as a science, for it filtered smoke 
and absorbed gas. All this progress led, therefore, to 
the shipment toward the end of the war, with troops 
who were going across, of the best and most protective 
mask that the world had seen. 

Starting a mask production effort in May, 1917, 
Americans turned out, up to June 1, 1918, 1,719,424 



GAS-MASKS 309 

respirators. Up to December 31, 1918, the total pro- 
duction had amounted to 5,692,499 respirators, of which 
there had been shipped overseas, up to the signing of 
the armistice, 3,938,808 completed masks. As to the 
quality of them, it is only necessary to say that they 
gave twenty times the protection aiTorded by the best 
German gas-mask. We protected our soldiers against 
the German poisons etfectively, and Crowell and Wil- 
son write: ''No American soldier was ever gassed 
because'of the failure of an American gas mask, and 
such casualties as did occur were due to the fact that 
the masks were not quickly enough utilized when gas 
was thrown over, or because the soldiers were un- 
aware of the presence of gas. With such protection, 
there was no longer reason to fear that the frightful- 
ness of chemical warfare would reduce Americans' 
morale." 

In France, from February 1, 1916, to November 11, 
1918, about thirty million M-2 masks were made ; and 
the ARS, which is somewhat of the German type and 
which was manufactured in France beginning Febru- 
ary, 1917, was made to the extent of about five million. 
In England, out of fifty million masks produced, nine- 
teen million were box respirators. In the manufac- 
ture of Tissot masks there were 100,000 large models 
from the year 1916 to July, 1918, and 600,000 small 
models from April 1, 1917 to January, 1919. France 
supplied other powers with 3,240,000 units of protec- 
tive equipment. 

The World War became toward its close literally 
a chemical one. In July, 1918, the German Divisional 
Ammunition Dump contained 50 per cent, of gas 



310 THE EEIGN OF EUBBER 

shells; and in May, during the G-erman preparation 
for attack on the Aisne, the artillery programs con- 
tained as much as 80 per cent, of gas shells for cer- 
tain objectives. Chemical warfare really includes in- 
cendiaries, smokes, and gases. The aeroplane and 
the dirigible on both sides used incendiary bombs, as 
well as gas shells. Which is worse, to be suffocated by 
the smoke of burning buildings, or put out of action 
by phosgene or chloracetophenone I All war is pain- 
ful and dangerous. We naturally think in terms of 
personal experience. 

When chemistry becomes better understood, we 
shall be free from the idea of the mystery of it; and 
the pain and suffering from these numerous types of 
gas will be found, in point of fact, to be less than 
that from shrapnel and projectiles. The horrors of 
gas have been preached from press and pulpits. Yet 
facts do count; and when the Surgeon-General tells 
us that the man who was injured by gas alone on the 
field of battle has twelve times as many chances for 
recovery as the man wounded with bullets and high ex- 
plosives, we must be impressed. Likewise, bullets, 
high explosives, and other methods of warfare than 
gas, were responsible for twenty-five times as many 
blinded men; and, in addition, the explosives caused 
losses of legs and arms to an extent that gas could 
not and did not do. Even tuberculosis was really less 
frequent among those gassed than among those who 
enlisted and were not gassed. It would seem apparent 
that the evidence is rather in favor of the humanity 
of gas warfare. This attitude is not the thoughtless 
one of propagandists ; but it is really the cold, definite 



GAS-MASKS 311 

conclusion of teclinical men who have nothing to gain 
by making such statements other than the satisfac- 
tion of speaking truth to those who would read it. 

General Fries well states: *'As between the mask 
and poisonous gases, we have the old struggle of the 
battleship armor against the armor-piercing projec- 
tile. While the armor-piercing projectile has always 
had a little the better of the game, it is just the re- 
verse with gases." Nevertheless, protection in the 
form of further development is a vital national need. 
New chemicals will continue to be made; it is easy 
to manufacture them secretly, test them, and get ready 
for any war which might come. Those of us who are 
in chemical industry are inclined to believe that all 
the treaties that may be signed will not eliminate 
danger from the gas attack. As long as the possibil- 
ity of war continues, we shall have a problem of de- 
fense which should be met by research work on all de- 
fensive appliances. If gas-masks can be made having 
perfect resistance in the face-piece, a high degree of 
gas absorption in the canister, availability through 
ease of manufacture, comfort in inhalation and ex- 
halation, and a glove-like, easy fit upon the head, that 
nation which can produce such protective appliances 
will at least, be in the strongest defensive position. 

Eesearch of this character is of vital importance to 
this country, and cooperation to that end should be 
sought; for the world's history shows that no weapon 
of offense has ever been discarded. 



CHAPTER XX 
BALLOONS 

The captive balloon has been called the eye of the 
artillery. With this balloon five thousand feet in the 
air, swaying at the end of a long steel cable, the ob- 
server sat in his basket. He was truly, in the World 
War, the chief means by which fire from the camou- 
flaged batteries came to be accurately placed. The 
World War was one based on mathematical science, 
for the barrage and the exact placement of shells were 
factors which, in no small degree, were responsible 
for the holding of the lines on the Western Front. 
No concealment was possible for this observer; he 
was held aloft by hydrogen retained in a rubberized 
fabric bag of peculiar design. His telephone wires, 
insulated by vulcanized rubber, went down through 
the center of the steel cable. Dependent he was, 
therefore, in more ways than one upon rubber for the 
success of his work. It was no easy job. Although 
he floated over a beautiful country, yet the landscape 
was not his to view, except in the particular spots 
where shells struck and burst. Many perils were 
his; the rapidly moving aeroplanes from the enemy's 
line were peculiarly enemies, for they were specially 
commissioned to hunt down captive balloons and set 
them on fire with incendiary bullets. The balloon 

312 



BALLOONS 313 

was the target both of long-range guns and of air- 
craft. 

It has been stated that the average life of a kite- 
balloon on an active sector of the Western Front was 
estimated to be about fifteen days. Some of them 
lived only a few minutes, and the War Department 
reports that only one American balloon passed un- 
scathed during the whole period of American activity 
on a busy sector. It is interesting to the rubber man 
also to* read the reports that show how five or six 
months of non-war service will deteriorate the balloon 
fabric; although there are many instances of useful 
service longer than this. A dangerous business is 
this ballooning, but a vital one. To the humble ob- 
servation balloon goes much of the credit for the 
marvelous accuracy attained by artillery during the 
war. 

Balloons have been known for many years. The 
Montgolfier brothers, Frenchmen, in November, 1782, 
made a paper-bag balloon. When filled with hot air, 
this was large enough and buoyant enough to permit 
them to send up a sheep, a rooster, and a duck. 

I remember well how, as a boy, ballooning attracted 
me, after a visit of Captain Baldwin to the County Fair 
in the small town where I was brought up. I suppose 
most small boys have seen the balloon and the para- 
chute-jump made by these early spectacular perform- 
ers, who entertained the multitudes by ascending in 
spherical balloons and jumping from them. Then it 
was simple for us to study how balloons were made. 
With light-weight paper, scissors, and paste, it was 
easy to lay out the parts in the barn and to construct 



314 THE REIGN OF EUBBER 

the panels and gores for making balloons larger than 
could be bought from the fireworks store. We sent 
them up with hot air generated from a wood fire, with 
a piece of tile as a chimney and a concentrator; and 
night after night, during the summer, when the air 
was clear, these little balloons have floated above the 
country, dropping parachutes with Japanese lanterns 
in them, scaring the timid with fear of fire, but stimu- 
lating in the soul of American youth that future love 
of the air which was to develop so rapidly and so suc- 
cessfully during the war. We but repeated in a small 
way the Montgolfier brothers^ exploit. 

A little later, after the brothers had performed their 
feat, two other Frenchmen, De Eozier and De Vilette, 
ascended to a height of three hundred feet and came 
down safely. From that day to our Civil War, bal- 
looning remained a spectacle of the circus and a sport 
for the intrepid. But during the Civil War, balloons 
were used for observation to a limited extent. Later 
on, they were anchored by means of cables, for sight- 
seeing purposes ; and many is the person who, having 
gone up a few hundred feet in a spherical balloon 
swaying and tossing in the wind like a cork on rough 
water, became seasick and weary as the result of a 
rather harrowing experience. For observation pur- 
poses, this tossing about of the spherical balloon made 
its use uncertain ; it was difficult to obtain exact data, 
because the observer was frightfully seasick. 

What substances to employ to retain hydrogen in a 
balloon was ever a problem. Special varnishes made 
of linseed oil were used in the old days of circus bal- 
loons. The first "inflammable air'^ balloon made of 



BALLOONS 315 

silk was launched on the European continent by the 
Roberts brothers and J. A. C, Charles in the year 1783. 
G. J. Wright in 1803 suggested, however, strong cam- 
bric muslin, rinsed in drying oil or varnished with a 
solution of resin or gum lac with linseed oil. He found 
that the compositions for varnishing balloons had been 
variously modified, but, upon the whole, the most ap- 
proved appeared to be the bird-lime of Faujas St. 
Fond. However, he wrote: *'As the elastic gum 
known by the name of Indian rubber has been much ex- 
tolled as a varnish, the following method of making 
it, as practiced by Mr. Blanchard, may not prove un- 
acceptable: Dissolve elastic gum in five times its 
weight of rectified essential oil of turpentine, by keep- 
ing them some days together. Then pour one ounce 
of this solution in eight ounces of drying linseed oil 
for a few minutes; strain the solution and use it 
warm.'' He proposed that the parachute be con- 
structed of varnished cambric muslin. 

The first ones to deviate from the old spherical shape 
to something of the kite idea were the Germans, who 
made a balloon known as a Drachen, sixty-five feet long 
and twenty-seven feet in diameter. This Drachen 
had an open under-rudder which, filled with air, made 
the balloon somewhat more steady than without it. 
A series of tail cups, like little parachutes, served to 
prevent the balloon from bobbing and swaying too 
greatly. It was a long cylindrical object, with a series 
of ropes from a band around its equator carried down 
and concentrated at a ring. From this ring the cable 
ran down to the ground. The Drachen was, however, 
unstable in high winds. The likeness of the original 



316 THE EEIGN OF EUBBER 

Drachen, with its various modifications, to a German 
sausage led to the adoption of the name ''sausage" in 
slang expression. 

Captain Caquot of the French army met the situa- 
tion with a kite-balloon that had such superior stability 
in high winds, that it came rapidly into general use in 
the armies and navies of all the combatants. This new 
balloon, which has been known as the Caquot type of 
kite-balloon, was ninety-three feet long and twenty- 
eight feet in maximum diameter; as usually con- 
structed, it had a capacity of 37,500 cubic feet of hy- 
drogen. 

The Caquot balloon, in principle, consists of an elon- 
gated, rubberized fabric envelope, larger at one end 
than at the other. The rubberized fabric is a layer 
of rubber between two layers of thin, cotton cloth cap- 
able of resisting the outflow of hydrogen. At the lee 
end, are stabilizers of much lighter rubberized fabric, 
connected in such a way that the wind blows into these 
stabilizers, filling them out and causing the balloon 
to soar up like a kite. Near the top, two of them, some- 
thing like big wings, have the appearance of elephant- 
ears ; and one acts as a sort of a vertical under-rudder. 
Even with these stabilizers the balloon would not be 
steady enough in the wind, if it were not for a rub- 
berized fabric diaphragm which lies inside on the bot- 
tom of the balloon and is called a ballonet. The func- 
tion of this ballonet is to give a space of variable 
volume, so that when the hydrogen in the balloon con- 
tracts because of variation in temperature occasioned 
by altitude the balloon may be kept taut. This taut- 
ness is accomplished by the inflow of air caught 



BALLOONS 317 

by a scoop on the under side of the envelope. The 
air flows into this ballonet space, raises it, and main- 
tains sufficient pressure in the envelope to preserve its 
shape. Without the ballonet, the kite-balloon would 
become a shapeless and unmanageable mass of flap- 
ping fabric whenever the gas contracted. When the 
heat of the sun expands the gas, the hydrogen presses 
against the balloon, air passes out through the same 
scoop, and the envelope is kept taut. But if there is 
more expansion than the ballonet can acconmiodate, 
another important device comes into operation. This 
is the automatic gas-valve located in the top, near the 
front of the balloon, which operates at a determined 
pressure to let out hydrogen and thus always to main- 
tain the pressure in the balloon at a constant value. 
By this combination of devices, there was made an 
instrument of war observation, permanent and stable 
in the wind. Its ability to ascend more than five thou- 
sand feet gives to the observer a wide range of vision. 
The basket cables are connected to the balloon by 
rigging; in the basket, which is made of light but 
strong wicker, are the observers with their instru- 
ments. 

When the United States went into the war, our army 
and navy were virtually without observation balloons. 
The only company in this country that had systematic- 
ally studied ballooning was the Goodyear Tire & Rub- 
ber Co. of Akron, Ohio. With remarkable foresight, 
the officials of that institution had for a number of 
years developed a balloon organization. 

In the spring of 1910, with the aeroplane develop- 
ment under way, P. W. Litchfield, vice-president of 



318 THE EEIGN OF EUBBER 

the Goodyear company, looked into the future and 
saw great possibilities. He went to Europe in the 
summer of that year, made arrangements for a sup- 
ply of the precise cotton fabric required, and in the 
autumn began the experimental manufacture of free 
balloons. The first airship attempt was the Akron, 
which was made to fly across the Atlantic, but which 
met with an untimely explosion in July, 1912. 

The company continued to experiment with spherical 
balloons and had a considerable number of trained 
men engaged in their manufacture in 1917. 

When the emergency came, all joined hands in whole- 
hearted cooperation: the signal corps of the army, the 
navy, the United States Rubber Co., the Firestone 
Tire & Rubber Co., the Connecticut Aircraft Co., the 
Knabenshue Manufacturing Co., the B. F. Goodrich 
Co., and the Goodyear Tire and Rubber Company. 

Balloon fabric as used in kite-balloons was of three 
classes. The ballonet cloth weighed two ounces to 
the square yard; in it two plies were used with the 
threads parallel, and a thin layer of rubber was prop- 
erly vulcanized between them. So fine was this cloth 
that there were 118 threads to the linear inch of warp 
and filling. The main fabric of the balloon consisted 
of two plies of fabric weighing two and one half ounces 
to the square yard, one of them placed upon the other 
on the bias, with three and one half ounces to the 
square yard of rubber known as the sandwich layer 
between them. This two-and-one-half-ounce cloth was 
so fine that there were 128 threads to the linear inch 
of width. After it was made up into fabric, a pull of 
sixty pounds on a one-inch strip was required to break 



BALLOONS 319 

it. It was a delicate, skilled, careful operation to 
make balloon cloth ; only the finest of Sea Island cotton 
or the Sakellarides Egyptian cotton would answer. 
There could be no imperfections, for each little knot 
or each bit of dirt would mean a pinhole through which 
the hydrogen would leak. 

In the manufacture of rubberized balloon fabric, 
the raw cloth is first placed over a glass table il- 
luminated from below, where it is observed for im- 
perfections. This cloth is then coated with a thin 
layer of rubber cement. The rubber composition is 
one chosen after many experiments; each manufac- 
turer has probably a slightly different idea, but all 
the compositions are subjected to sunlight tests and 
other rapid determinations of length of life. Only the 
purest, cleanest rubber of the highest grade is used, 
and very little of any type of compounding ingredients 
except those conducive to perfection, to resistance to 
diffusion, and to resistance to the action of light and 
heat. It requires as many as thirty-two thin layers of 
cement to build upon the fabric the thickness of rub- 
ber required. 

After each layer of fabric has been spread and dried, 
one of the layers is cut into pieces on the bias and 
pressed upon the straight sheet with a thicker rub- 
ber layer between. Great skill is necessary in order 
so to lay on the rubber that the diffusion of hydrogen 
through it is a minimum. This doubled, long roll is 
then wrapped upon a drum and vulcanized. 

The details of the manufacture of the envelope are 
those of a high degree of creative skill. Strips or 
gores of fabric run longitudinally, each of these gores 



320 THE REIGN OF RUBBER 

being made up of panels in which the warp threads 
are perpendicular to the length of the gore. .Seams 
between the adjacent panels are made by overlapping 
the fabric and carefully cementing the edges together. 
Since dirt is so great an enemy of rubber, in punctur- 
ing it, only skilled workmen, usually girls are per- 
mitted to work in the balloon-room ; and they wear 
soft-soled slippers. Whenever balloons are handled on 
the floor of the great assembly-rooms, they are never 
dragged about on the cement floors, but are moved 
about on vacuum cleaned carpets of heavy canvas. 

After this long and careful process of manufacture, 
our balloons during the war gradually were assembled. 
Special riggers applied the rigging of rope. Certain 
rubber compositions were used on the outside of the 
envelope, designed after careful study to protect the 
sandwich layer of rubber. The purpose of these com- 
positions was to absorb the active or actinic rays of the 
sun, and also to keep out oxygen from the air. We 
generally adopted European standards of construc- 
tion; but we developed our own rubber compounds, 
times of cure, and methods of manufacture. American 
fabric burned more slowly than European balloon fab- 
ric, and thus when the balloon was struck by hostile 
bullets it gave the men in the observation-baskets more 
time to get away in parachutes. 

Small Caquot-type kite-balloons were used by the 
Navy Department for observation purposes on board 
ships in the spotting of submarines. There were also 
propaganda balloons. We find that up to the armis- 
tice the rubber companies and others in the United 
States produced 676 observation balloons for the 




Courtesy Official Photograph, U. S. Army Air Service 

UNITED STATES NAVY TYPE BLIMP DIRIGIBLE 




Courtesy Official Photograph, U. S. Army Air Service 

SPHERICAL BALLOON CAQUOT KITE BALLOON 



BALLOONS 321 

army, of wMch 481 were shipped overseas, and that 
t^ey made 129 supply balloons and 215 propaganda 
balloons. 

But these kites were not the only aircraft in which 
rubber was used. For while fewer in number, diri- 
gibles were better known to the public. These were 
made for the Navy Department. The Bureau of Con- 
struction and Repair had been studying dirigible con- 
struction ; and in February, 1917, the Secretary of the 
Navy Wks ordered to proceed with the construction of 
sixteen such air-ships. 

The B-type dirigibles were 160 feet long and of 
85,000 cubic feet capacity. Equipped with one one- 
hundred-horse-power motor, they were capable of mak- 
ing a speed of forty-five miles an hour, with an en- 
durance of about sixteen hours. A larger ship known 
as the C-type, was 192 feet long, with a gas capacity 
of 190,000 cubic feet. This air-ship had a possible 
speed of sixty miles an hour and an endurance of 
forty-seven hours. It was one of this type that flew 
in 1919 from Montauk to Newfoundland, with the ex- 
pectation that it would take part in a transatlantic 
flight. But unhappily, in a high wind it broke loose 
from its mooring and was blown out to sea. This acci- 
dent constitutes one of the many tragedies connected 
with aircraft. 

In making the rubberized fabric for the air-ship of 
the non-rigid type, the same principles that have al- 
ready been described in the discussion of kite-balloons 
were used. The same care in the manufacture of this 
cloth was maintained. The envelope was stronger be- 
cause made of two plies of heavier cloth. 



322 THE EEIGN OF RUBBER 

Because of the smallness of its size, its compara- 
tively low cost, and the ease with which the envelope 
can be erected or deflated for shipment, there are 
great advantages in the non-rigid type of air-ship. 
Its most serious disadvantage lies in its dependence 
upon careful control of gas pressure within narrow 
limits. If the pressure rises too high, the envelope 
may burst, although ampie valves of a proper design 
limit this risk. It is, however, equally fatal for a loss 
of pressure to permit the envelope to lose its shape, 
because nothing is quite so dangerous as a sagging 
envelope. 

All the steering-equipment, rudders, fins, and the 
car are slung upon the outside of this envelope by 
wire or manila rope through cemented-on patches. 
During a wind the stresses in a sagging envelope may 
therefore be enough to tear this light thin cloth ; with 
tearing of the cloth, comes destruction of the balloon. 

Consequently the problems in dirigible construction, 
and we may say in all types of balloon construction, 
lie largely in having the strongest and lightest fabric ; 
one of sufficient strength so that when reasonably well 
designed the application of sudden and irregular loads 
upon any of the attachments cannot tear the cloth. 
The fabric must be permanent in the sunlight. Resist- 
ance to the diffusion of hydrogen is an important 
problem in practical operation. While it is always 
required that this be kept at a minimum, when one 
considers the losses of hydrogen from the operation of 
valves in the expansion of the gas on ascending into 
the sun, it is safe to say that losses by diffusion are 
minor factors. 



BALLOONS 323 

The so-called semi-rigid air-ship also has an enve- 
lope of rubberized fabric. A girder keel gives it stiff- 
ness and renders it less dependent on gas pressure 
for the maintenance of shape. Here a lower gas pres- 
sure and hence a lighter weight of fabric is permis- 
sible than in the non-rigid air-ship. The bending 
forces are so distributed that the keel takes compres- 
sion while the fabric receives a moderate tension. 
Therefore, it is possible to give the semi-rigid ship 
an exceptionally light construction, and so to permit a 
relatively greater useful load to be carried to a higher 
altitude than with other types of equal size. With 
the exception of the keel in the envelope, small, semi- 
rigid air-ships resemble non-rigids in their general 
features. They are more costly and less easy to erect. 

The most spectacular type used during the war was 
the rigid air-ship of the Zeppelin type, which employed 
very little rubber in its construction. Probably it is 
the largest and most complex of all known types of 
aircraft — largest in carrying capacity, highest in 
speed, most intricate in the structure of its dura- 
luminum girders and wire. Triangular-shaped gir- 
ders make up its backbone. On the outside a ply of 
cloth is tightly drawn around the girders and coated 
with aluminum, water-tight ''dope." Inside the gir- 
ders, within the hull structure, are arranged sepa- 
rate gas-bags, usually made of a single ply of light 
cotton cloth lined with a thin layer of so-called ' ' gold- 
beater 's skin," to give gas tightness. Goldbeater's 
skin is made from the entrails of cattle; it is a thin 
membrane almost perfectly gas-tight and very light. 

Since air-ships have a promising future, there 



324 THE EEIGN OF RUBBER 

is a large opportunity for development work in 
the scientific construction of fabrics to permit very 
much greater resistance to tearing, with no increase 
in weight. The rate of deterioration of rubber in the 
sunlight through oxidation is one of the important 
problems, but one which, I believe, has been largely 
solved. Rubber fabric, though, should be applied in 
greater degree to these aircraft. When the problems 
of construction, explosion, permanence, and strength 
of fabric are more nearly solved, the great future of 
the air-ship will be more completely realized. 

The time will surely come when air-ships of enorm- 
ous size, capable of remaining in the air even if an en- 
gine stops, will run between London and New York or 
across the continent. Then the business man will be 
able to go from New York to London in forty-eight 
hours. Since speed in business has come to be so 
necessary, it seems not unlikely that the demand of 
the future will require a minimum of time in long- 
distance transportation ; probably this high speed most 
certainly and safely can be attained through lighter- 
than-air craft. 



CHAPTER XXI 
THE FUTURE OF RUBBER 

A laudable future for any industry, man, article, or 
substanpe can be achieved only because of service 
rendered to mankind. *'For whosoever hath, to him 
shall be given, and he shall have abundance ; but who- 
soever hath not, from him shall be taken away even 
that which he hath." This fundamental truth forms 
a basis for prediction. It is idle for one to dream 
when dreams but express wishes. It is useless to pre- 
dict, when predictions formulate only hopes. One 
can, however, forecast possibilities of growth based 
upon natural properties of usefulness. ''Whosoever 
hath" means characteristics, physical in the case of 
rubber, mental and moral in the case of an individual 
man, a company, a corporation, or an industry. Rub- 
ber and rubber companies, we believe, can become 
greater in a commercial sense only if the qualities of 
rubber are superior and if they render valuable service 
to those who would use their products. 

Does rubber have properties natural to it which, 
when expressed in the form of articles made and used, 
will probably increase the extent of its service? 
The question is its own answer. There is no sub- 
stance, and essentially every one known has been tried, 
to take the place of rubber. Rubber serves, and serves 
remarkably. If the pages which I have thus far 

325 



1 



326 THE REIGN OF RUBBER 



written have accomplislied their purpose, they indicate 
certain fundamental characteristics by which rubber 
is distinct from any other known material; and they 
show that rubber has worked itself into life economy 
by virtue of the fact that it performs definite, valuable 
functions, not artificially stimulated but naturally 
possessed and given. Some phases of these character- 
istics may be reviewed from a different point of view. 

Although food, shelter, and clothing are the three 
necessities for our physical welfare, the relations with 
our fellow-men give us happiness, and these relations 
are modified greatly by means of communication and 
transportation. We have already spoken of the tele- 
phone and the telegraph, with their rubber parts, by 
which wire communication is maintained. 

The good fellowship among men is in no small way 
engendered by freedom of intercourse over wires. 
There are millions of intelligent human beings on our 
earth to whom the telephone has not come — a vast 
field for expansion with boundless possibilities for 
service. The telephone will span the sea. Distant 
people will talk to each other. When persons all over 
the world can understand each other and can freely 
and rapidly communicate, then, and not till then, will 
wars cease and peace on earth be a reality. 

Communication without wires is a new development 
which has come along so rapidly in the last few years 
that it bids fair to extend to almost unlimited possibil- 
ities. Since the uses to which radio can be put are 
diversified, it is certain to bring about changes in 
life's every-day affairs. It will, through finely devel- 
oped broadcasting stations, serve to bring in to homes. 



THE FUTURE OF RUBBER 327 

news, communications, entertainments, and education 
of wonderful value. For communication from ship 
to ship or from shore to shore and between aeroplanes 
in the air, for making ships safe on ocean and lake 
when in heavy fogs, for out-of-the-way places where 
wire installation would be expensive and impracticable, 
wireless constitutes, in addition to the conveying of 
regular commercial messages, a development of vast 
importance. 

What part will rubber play in wireless communica- 
tion of the future 1 It plays a part to-day ; for, of all 
the substances thus far known, rubber is the one which 
for wires possesses the greatest flexibility and insulat- 
ing properties, and which in the form of hard rubber 
has greater dielectric capacity than any other sub- 
stance, with less dielectric loss. The use of hard rub- 
ber and other rubber products in connection with radio 
has every possibility of increased use. 

Regardless, however, of both wire and wireless com- 
munications, we still do and doubtless always shall 
reduce our ideas to writing. The permanent record of 
business intercourse, the printing of books and news- 
papers, lie in the field of communication which has been 
developed to a great degree already, but which has pos- 
sibilities for further growth. We have spoken already 
of the typewriter. I wonder whether more parts of it 
will not ultimately be made of rubber, — a construction 
reducing the noise to a degree approaching silence? 
Perhaps some enterprising inventor will study the 
voice-waves, so that a telephone typewriter will be 
worked out, permitting the direct transfer of the voice 
to letters on paper. To wonder whether rubber will 



328 THE REIGN OF RUBBER 

play a part in such an enterprise, is, I suppose, to 
dream. 

In the printing of books and newspapers, the last 
few years have witnessed changes produced by the use 
of the rubber ink-spreading rolls, which have given 
marked eSiciency and improvement. Despite the fact 
that oils are used for inking purposes, rubber 
has been found to resist them relatively well, to with- 
stand in these rolls the change of climate, and to give 
a marked superiority to the permanence of operation 
of printing-presses. When, however, in connection 
with rubber ink-spreading rolls, the water-ink, which 
is a development of recent growth, comes to be gen- 
erally used, all phases of the printing industry will 
economize time and money and gain higher speed. 
This development of considerable value will have been 
made possible by rubber and rubber rolls. 

Because supplies of wood for wood pulp are rapidly 
decreasing, materials must be found to serve in the 
manufacture of paper. We shall be able to grow, with- 
out doubt, a sufficient quantity of cellulose ; if, though, 
it fails to have the properties which wood pulp pos- 
sesses to-day, it may be necessary to follow out the 
suggestions recently made of using rubber in connec- 
tion with it. By virtue of its adhesiveness, rubber 
may give us book ai^i news-print paper of greater value 
than we now have. Something is certain to be done, 
for the need is here and will become more and more 
marked with time. 

But it is in the field of transportation that rubber 
will continue to extend its usefulness. Whatever may 
be your definition of the word ''civilization", one 



THE FUTUEE OF RUBBER 329 

thing is true : the difference between human life as we 
live it and the lives lived by our forefathers back over 
the centuries lies in the means that have been used to 
overcome elemental conditions. Civilization, be it 
moral or physical, is marked by a development of hu- 
man facilities. To use and enjoy them, men and goods 
must be moved from place to place. Thus transporta- 
tion holds the key to the world's progress; and ''the 
history^of the highway by land and sea is the history 
of civilization and the mark of the progress of man." 
We have but to compare travel upon the continent 
in the days of the old French diligence to realize how 
completely our Kves have altered in a short span of 
years because of improved transportation facilities. 
In an interesting volume on ' ' Travel in the Last Two 
Centuries of Three Generations" by S. R. Roget, he 
describes a trip taken in 1818 in the United States. 
He says that Dr. P. M. Roget on May 18 of that year 
left Philadelphia and arrived the same night at Eliza- 
bethtown, eighteen miles west of Lancaster, and again 
on May 29 he passed through Harrisburg to Chambers- 
burg. He remarks that from Harrisburg the roads 
were very bad. The bridges were constructed of wood, 
except the piers, which were of stone, and were cov- 
ered by wooden roofs. "The roads, instead of wind- 
ing round the mountains, are carried almost straight 
across them, and appear to have had very little more 
labor bestowed upon them at any time than that of 
clearing away the timber which grew upon them." 
The difficulties of transportation described in the an- 
ecdotes of this interesting volume leave no doubt in 
our minds that our modern life could not be lived with- 



330 THE EEIGN OF EUBBER 

out the railroads or without improved highways. 
Thus, our human progress has been built upon the free 
movement of goods and of men. Just as England has 
been made great by the use of the ocean as a highway, 
so the United States has in the short space of a hun- 
dred years been made great by her rail transporta- 
tion, the most advanced and complete the world has 
ever seen. 

Eubber, just as certainly as steel, has aided the de- 
velopment of the railroads, the signaling system, the 
ocean ships, and many other fundamental things that 
have made transportation changes possible. In va- 
rious ways unsung it plays a great and vital part. 

During recent years, however, we have watched the 
growth of a new form of transportation — that of the 
trackless car, the motor-car, the truck. Here, in a 
most spectacular way, the rubber tire and various 
other rubber parts have come to be vital. In the fu- 
ture, the development of the improved highway, be it 
the macadamized road or the cement or brick pave- 
ment, will surely play an increasingly important part 
in transportation. The railroads ever will be the main 
arteries upon which tonnage and speed can be main- 
tained, but the highway more and more will become the 
feeder. In our cities the trolley-car conveys us from 
place to place. The motor-bus is the trackless street- 
car of the future. It is economical, convenient, quiet, 
and subject to a degree of flexibility not possessed by 
the electric tram. No dream is necessary to look for- 
ward to cities in which motor-buses will be the pre- 
dominant means of human conveyance. So far as 
goods are concerned, with the railroad it is necessary 



THE FUTURE OF RUBBER 331 

to load them at a factory, haul them to a station, un- 
load, them in a car, unload them again at a distant ter- 
minus, load them into a van, haul them to the consumer, 
and unload them again. The motor-truck, contrari- 
wise, permits one loading and one unloading, a saving 
in energy and time. 

A vast extension in the use of the motor-car is a log- 
ical forecast, and with it an expansion of the rubber 
industry. In 1896 there were but four gasolene auto- 
mobiles in the United States ; in 1916 there were 3,500,- 
000; and at the beginning of 1922 there were nearly 
10,500,000 — one car for every ten people. There are 
about 3,000,000 motor-cars on the farms, that is to say, 
the farmers own about one third of the motor-cars; 
while in the cities of 500,000 or over there are only 9 
per cent, of this total registration. There are in 
America 24,351,676 homes. It is hardly possible that 
in the future there will be one car for every home, but 
there are more than 6,750,000 farm homes from which 
motor-cars might serve well to carry food to city cen- 
ters. Eventually farmers will insist upon further im- 
proved highways, and demand the same facilities for 
communication with their fellows that are afforded to 
others. So far as the ability of the people of this 
country to purchase motor-cars is concerned, it is quite 
probable that a registration of 15,000,000 passenger 
and commercial cars within the next five or six years 
will be realized. 

These figures refer only to the United States, which 
has 6 per cent, of the population of the world, 7 per 
cent, of the land, and 83 per cent, of the motor vehicles. 
In the great continents of Asia, Africa, and South 



332 THE EEIGN OF RUBBER 

America, as well as Europe, the registration of motor- 
cars has not approximated that in America. Great 
Britain and Ireland, for instance, afford only an aver- 
age of one car for every 95 people ; while China, on the 
other hand, has one for every 54,708 persons. The 
wealth of many countries is sufficient to afford motor- 
cars to carry food products from farm to consumer. 
It seems reasonable to suppose that the countries where 
highway development has proceeded most rapidly will 
be first to demand and obtain sufficient motor-cars. 
Thus, the countries of Europe will, in all probability, 
rapidly acquire them. In the other countries, how- 
ever, the spread of the motor-car will depend upon 
highway development. With this development will 
come exchange of commodities and personal relations 
that will lead to increase in the national wealth and 
ability to purchase motor-cars. As a consequence, the 
need for rubber goods of all descriptions will grow 
manifold. 

Let us see what these possibilities mean to the fu- 
ture production of tires in the United States. The 
world registration of cars at the beginning of 1922 was 
12,528,000, an increase of 1,606,000 over that of the pre- 
vious year. In the United States the increase will 
probably not continue at that rate; but, on the other 
hand, elsewhere a higher rate will no doubt 
be attained. Assuming the world to add 1,606,000 au- 
tomobiles and trucks each year for six years, there 
would be at the beginning of 1928, 22,164,000 cars, a 
total increase of 75 per cent., a change not only possible 
but highly probable. At the rate of three tires per car 
per year, the rubber industry of the world would sup- 



THE FUTURE OF RUBBER 333 

ply more than 66,000,000 tires to the consumers in that 
year. They will be cord tires for passenger-cars, with 
a marked increase in the use of the solid tire on the 
bus and the truck. Including inner tubes, we assume 
a weight of fifteen pounds of crude rubber to the tire. 
For transportation purposes, therefore, we are justi- 
fied in a prediction of a use for tires alone of 990,- 
000,000 pounds or 440,000 long tons of raw rubber in 
1928. The productive capacity for tires in America 
to-day is probably not far from 44,500,000 yearly, and 
that of all other countries, 10,500,000, or a total of 
55,000,000. The world will need to increase its capac- 
ity before 1928 by 11,000,000 tires a year to care for 
the demand. 

In transportation in the sky rubber has played and 
will continue to play a most vital part. The dirigible 
has come to stay ; the fatal accidents that have startled 
us during the last few years serve but to indicate how 
we have attempted to run ahead of demonstrated 
experience. Rubber in the making of balloons to hold 
hydrogen or helium has proved itself valuable and will 
prove itself more so. The business man, with his con- 
tract to be signed, will fly from his office to the trans- 
atlantic dirigible field, where the great three or 
four-million-cubic-foot aircraft will be moored. He 
will ascend in the elevator inside a mooring mast and 
walk into his cabin as readily as he now does into the 
state-room of the ocean liner. When all is ready the 
dirigible will move rapidly and safely, avoiding the 
storms and the high winds by her ability to rise above 
them or fly below them. Within the space of a day 
the business man will find himself landed upon the 



334 THE EEIGN OF EUBBER 

other side of the water as safely as he now could in 
five days on board ship. 

This change is surely no greater than the change in 
ocean transportation over the last two decades. With 
non-combustible helium as the gas, with an oil engine 
rather than a gasolene one to furnish the motive-power, 
and with rubber to hold the helium, the fire risk will 
be brought down to a minimum. The only force 
to be avoided will be the wind, which for these 
new dirigibles will be, if anything, of less moment than 
on board ship ; the advantage will lie with the aircraft 
in its capability of dodging the storm. Certainly there 
can be no danger from collision, for the radio will serve 
to locate promptly both direction and distance and 
the presence of any other aircraft in the same range. 
Will the supply of helium be found? Yes. For mod- 
ern chemistry is demonstrating decomposition of the 
older elements into their simpler ones, and helium is 
one of the simpler ones. 

Other rubber goods will be required. The people 
beyond the seas will need rubber footwear, as do we. 
Homes will use increasing quantities of rubber. 
Mines, mills, and railroads are enlarging everywhere, 
requiring increased amounts of rubber. Sports, too, 
are spreading. All the world develops slowly along the 
same lines. New uses for rubber will arise, not the 
least of which will be the employment of rubber in 
building construction. It is no idle prediction which 
one reads in the reports of the United States Forest 
Service that the supply of timber in this country is 
year by year growing smaller. The tremendous waste 
that has occurred in lumber and the fact that trees 



THE FUTURE OF RUBBEK 335 

take so long to grow, give to the future of building con- 
struction a real problem. The time will come when 
we must grow our own structural materials or dig 
them out of the ground. Then we shall build our 
houses of cement or rock or grow them. Perhaps we 
may construct them of hard rubber. Some day we shall 
discover how to produce more esthetic colors in rubber 
compositions ; then rubber may replace wood for struc- 
tural purposes. 

About 70 per cent, of the rubber consumed has been 
in tires. If we consider tires to consume even 80 per 
cent., the total demand for raw rubber in 1928 will be 
550,000 long tons. 

Yet a serious question confronts us: can there be 
produced in the world crude rubber enough to supply 
this tremendous demand! There were planted in the 
Far East, at the end of December, 1921, a matter of 
3,321,000 acres. This was in British Malaya, the 
Dutch East Indies, Ceylon, South India, British North 
Borneo, French Indo-China, Burma, and other coun- 
tries. Still the area in square miles of the Dutch East 
Indies is 735,000; of the Federated Malay States, 
27,506; of the Island of Ceylon, 25,332. We neglect 
here, too, any consideration of the enormous areas in 
South America and Africa that are yet jungle and 
where rubber-trees may be planted and grown, pro^ 
vided man will be enterprising enough to go into those 
territories, open them up, and provide means of trans- 
portation and labor. The question seems to be one of 
cultivation of virgin land for raw rubber production. 

We have, therefore, only scratched the surface of 
the possibilities of rubber production. Each of these 



336 THE REIGN OF RUBBER 

countries, to be sure, contains many areas that are 
not capable of growing rubber-trees; but I believe it 
safe to predict that were the world-demand sufficient, 
there could be a hundred times greater production than 
even the anticipated figures indicate, and at costs of 
production sufficient to maintain a relatively low mar- 
ket, with profit to the producer and economy for the 
consumer. 

One of the incidents of the future will be the 
disappearance of wild rubber. Cultivated rubber has 
succeeded because of the suitability of soil, the sup- 
ply of food and labor, and the enterprise of govern- 
ments and individuals in the development of planta- 
tions and transportation. Trees are trained to yield 
larger returns ; coagulation has become a simple proc- 
ess. There is no element of rubber cultivation that 
cannot be repeated by plantations in any part of the 
world where rubber trees can grow. 

Yet with all this development of the use of rubber 
and rubber goods, may not the future be limited 
by a shortage of power? Oil, to be sure, is essential 
to the operation of a motor-car, coal is needed to run 
factories, and electricity is required to light them. 
The geologists tell us that the coal supplies are run- 
ning out, that the supply of oil is limited. However, 
there are many unexplored lands where oil may yet 
be found. So far as a liquid motor fuel is concerned, 
there can be grown all over the world, wherever crops 
are possible, plants that yield large quantities of cel- 
lulose, from which pure alcohol can be made. Alcohol, 
by proper adaptation of carburetors, can be made to 
burn efficiently in a motor-car. Perhaps rubber may 



THE FUTURE OF RUBBER 337 

yet furnish fuel to motor-cars. It can now, by proper 
treatment, be converted into combustible oil. As far 
as coal for heat and power is concerned, so long as 
the heavens give forth rain, there will be rivers; so 
long as there are rivers, they will run down mountains, 
and in so doing give sources of white coal or hydraulic 
power, which can be changed into electricity and car- 
ried over long distances. No; I doubt if there is 
any possibility of the shortage of power, heat, or 
light. - 

But the other raw materials — sulphur, zinc oxide, 
black, and the other products used in rubber com- 
pounds — ^will they last? Sulphur occurs in so many 
forms that, so long as the world stands, there will be 
plenty of it for every purpose desired. Zinc oxide is 
more of a problem ; its present sources are just enough 
limited to warrant a bit of thought. But yet, in con- 
junction with lead, it is widely distributed in huge 
quantities ; and chemists can separate the lead, freeing 
the zinc oxide needed for rubber. Carbon-black, how- 
ever, made from natural gas, is one of the substances 
that some time during the future will disappear. 
Chemists will be ready to replace it with pigments, 
equally serviceable substances for use in rubber goods. 
The field from which to draw mineral powders is too 
vast to cause any concern, were several of the well- 
known ones to be exhausted. 

Cotton constitutes a problem of considerable mo- 
ment to the rubber industry, because of the operation 
of the boll- weevil. How rubber men would welcome the 
elimination of that pest! The boll-weevil is a most ac- 
tive little insect and one whose destruction requires 



338 



THE EEIGN OF RUBBER 




THE FUTURE OF RUBBER 339 

the cooperation of chemists in finding poisons which, 
when applied to the ground or other places during his 
hibernation periods, will kill him. If the boll-weevil is 
not definitely restricted, then the predictions of the 
Department of Agriculture may unfortunately be 
realized, for one of the investigators says: '' To-day 
I predict that unless something be done that will defi- 
nitely and speedily stop the crime -of early planting, 
the entire cotton growing industry in the United States 
south fff the thirty-second degree of latitude will 
within the next ten or fifteen years be completely wiped 
out of existence. And that within the next thirty 
years the great cotton industry of the United States, 
formerly considered almost like a monopoly which, 
from a world production standpoint, has already been 
reduced by early planting from 67.9 per cent, in 1905 
to 56.7 per cent, in 1915, will have to take a back seat 
to that of British India." Cotton, therefore, is men- 
aced, but can be saved. Perhaps rubber milk sprayed 
upon the hibernation homes of the weevil might en- 
tangle him and hinder his growth. 

The research laboratories in the great factories em- 
ploy chemists, physicists, and engineers whose business 
it is to create processes and products. New uses 
for rubber are constantly finding their way into 
the markets. The dreams of to-day become the real- 
ities of to-morrow; possibly, often not in the same 
form in which they were originally dreamed, but 
nevertheless the dream made the suggestion. This 
intense activity will result in articles of increased value 
and service to the consumer. Rubber is a substance, 



340 THE EEIGN OF EUBBER 

which, in its ramifications extended by the forces of 
investigation, will certainly serve humanity in many 
more forms than it does to-day. 



THE END 



INDEX 



Abrasion, resistance to, 55 

Acetone extract, 104 

Accelerators, inorganic, 50; or- 
ganic, 53, 115; theory of, 52, 
115 

Acreage, plantation, 80, 335 

African rubber, 84 

Aging, 111, 118 

Air-brake, 276 

Akron, 14 

Aniline, 53 

Antimony sulphide, 62 

Automobile, future of, 331; his- 
tory of, 128; statistics, 331 

Balata, 87 

Balloons, 312; ballonet, 316; 
Caquot, 316; dirigible, 321; 
Drachen, 315; fabric, 314, 318; 
future, 323, 333; goldbeaters 
skin, 323; history, 313; kite, 
313; observation, 320; Zeppelin, 
323 

Bands, 233 

Barytes, 46 

Baseball^ 187; protectors, 188 

Bead, tire, 130 

Bell, Alexander G., 218 

Belting, axle lighting, 269; con- 
veyor, 269; elevator, 278; 
lacings, 268; power trans- 
mission, 264 

Bicycles, history, 120; statistics, 
125 

Billiard cushions, 204 

Bloom, 109 

Boots and shoes, classification, 
170; color, 178; designing, 172; 
history, 10, 11, 168; manu- 
facture, 173; production, 171; 



rubbers, 172; styles, 171; var- 
nish, 177 
Brazilian rubber industry, 66 
Brockedon, 25 
Cables, 209; gutta percha, 222, 

history, 224; rubber, 223 
Calender, 41; friction, 42, 266 
Cameta, 70 
Canning, history, 290; statistics, 

291 
Caoutchouc, derivation, 6 
Carbon black, 46, 59, 60, 61; 

particle size, 117 
Castilloa, 72 

Catalysts, see Accelerators 
Ceara, 84 

Chaffee, Edward M., 8, 35, 36, 41 
Chemistry, 99 
Chewing gum, 87 
Chicle, 87 
Chrome green, 62 
Choate, Rufus, 26 
Clay, 46 

Clothing manufacture, 182 
Coagulation, chemistry of, 101; 

plantation rubber, 77; wild 

rubber, 68 
Columbus, Christopher, 5, 63 
Compounding, 33, 44, 62 
Consumption, crude rubber, 82; 

future, 335 
Cotton, problem, 337. See Fabric 
Dipped goods, 255 
Divers suits, 281 
Drying rubber, 32 
Dunlop, John B., 121 
Dynamo, 206 
Elastic limit, 57 



341 



342 



INDEX 



Electricity, 205 
Energy, rubber, 56, 58, 60 
Erasers, 232 

Fabric, bicycle tire, 126; cord or 
thread, 132; in reclaim, 89 
pneumatic automobile, 131 
processing for tires, 131 
square woven, 132 
Faraday, 18, 206 

Fire engines, 235; steam, 237, 239 
Flap, tire, 135 

Football bladder, 204; guard, 204 
i'rictioning, 42; belt, 266 
Friction, belt, 266; tire, 131 
Gasikets, 275 

Gas masks, 298; Akron Tissot, 

306; description, 302; flutter 

valve, 303; hose, 303; P. H., 

302; M-2, 302; respirators, 302, 

■ 304; Tissot, 304 

Gas warfare, history, 300; as a 

weapon, 310 
Gloves, lineman's, 215; surgeon's, 

255 
Golf, history of, 189; greens, hose 

for, 285 
Golf balls, bursting force, 200; 
characteristics, 197; descrip- 
tion, 193; ducking, 192; energy 
imparted to, 199; flight, 197; 
gutta percha, 189; Haskell, 
191; history, 189; manufacture, 
195; tension, 195; statistics, 
188 
Goodyear, Charles, 9, 21, 41, 50, 

215, 280 
Goodyear, Nelson, 217 
Grading plantation rubber, 78 
Grain in rubber, 106 
Guayule, 84 

Gutta percha, 87; cables, 222 
Hancock, Thomas, 7, 12, 18, 20, 

25, 30, 71, 129, 153, 182, 237 
Hard rubber, original, 217; chem- 



ical composition, 112, 217; uses, 
218, 230 
Haskell, Coburn, 191 
Hayward, Nathaniel, 22 
Heels, 180 
Herissant, 65 

Herrera-Tordesillas, Antonio, 63 
Hev^a-brasiliensis, 66, 71 
Hooker, Sir Joseph, 72 
Hose, air-brake, 276; air-drill, 
275; air-signal, 277; coupling, 
238; fire-history, 236; manu- 
facture, 242; storage, 247; test- 
ing, 244; garden, 285; gasolene, 
280; oil, 278; radiator, 275; 
railway requirements, 277; 
sand-blast, 275; spray, 289; 
steam-heating, 277 ; suction, 
275; statistics, 277 
Hospital, rubber for, 249 
Howison, James, 71 
Insulated wire, aging, 213; manu- 
facture, 207; railway signaling, 
210; telephone, 221; war-time 
uses, 221; for homes, 212 
Jar- rings, 292; testing, 293 
Jeffery, Thomas B., 123 
La Condamine, 64, 66 
Latex, 66; analysis, 100; chemis- 
try, 100; colloidal state of, 99; 
weight per gallon, 101 
Leather, artificial rubber from, 20 
Life-preservers, 21, 280 
Lime, 52 

Lineman's blanket, 214 
Liners, 42, 140 
Litharge, 46, 52 
Lithopone, 62 
Machinery, 30 

Mackintosh, 7, 19, 182, 237 
Macquer, 65 
Magnesium oxide, 52 
Markham, Clements, 72 
Marks, Arthur H., 53, 94 
Masticator, 19, 30, 35, 4a 



INDEX 



343 



Matting, 250 

Milking machines, 295; rubber 
parts for, 295; care of rubber 
for, 296 
Mineral rubber, 61 
Mitchell, N. Chapman, 91 
Mixer, 30, 35 
Mixing, 36 
Motor-bus, 151, 154 
Motor -truck, 150; electric, 152; 

history of, 152; service of, 166' 
Oenslager, George, 53 
Oil-fields, rubber in, 278 
Ostromisleiisky, 114 
Packing, 273; super-heat, 274 
Palmer, John F., 124, 138 
Paper, rubber for, 328; industry, 

278 
Para rubber, 68 
Parkes, Alexander, 113 
Peachey, S. J., 114 
Peal, Samuel, 7, 65 
Permanent set, 58 
Photomicrographs, 116 
"Pickle," 29 
Pigments, 46, 116; classification, 

117; particle size, 117 
Plantation industry, 71; acreage, 

80; growth, 80; location, 80; 

origii^, 71 
Polymerization, 104 
Poly sulphide, 116 
Pope, Alfred A., 127 
Poppenhusen, Conrad, 218 
Priestley, Joseph, 6, 66 
Printers' rolls, 328 
Production, crude rubber, 80; 

future, 335 
Proteins, 100, 103, 105, 106 
Eadio, rubber for, 226; future of, 

327 
Railway signaling, 210 
Raincoats, 182 
Reclaimed rubber consumption, 97 



Reclaiming, 88; acid process, 92; 

alkali process, 94 
Resins, 103, 104 
Robins, Thomas, 269, 272 
Roxbury India Rubber Co., 8, 20, 
41 

Rubber boom, 81 

Rubber, chemistry, 99; colloidal 
state of, 105; definition of, 16; 
history, 5, 63; hydrocarbon, 
103; structure of, 103; solu- 
tions, 7, 19, 65, 107; plasticity, 
29 

Rubber industry, definition of, 15, 
29, 42; future of, 325; growth 
of, 7; history of, 7 

Sernamby, 70 

Shrinkage, 70 

Shrub rubber, 85 

Sloper, Thomas, 138 

Smoked sheet, 78 

Smoking wild rubber, 68, 78 

Soles, 181 

Solvents, effect on rubber, 107, 
116; petroleum as, 65; turpen- 
tine as, 65 

Sponges, 283 

Sport, rubber in, 187 

Spreading, 40, 183 

Stamps, 233 

Steam, use of in vulcanization, 23 

Storage batteries, 226 

Storage, crude rubber, 79; rubber 
goods, 118 

Stress-strain curve, 50; efi"ect of 
accelerators on, 54 

Sulphur, 9, 22, 26, 28, 51, 110; 
combination with rubber, 108 

Sulphur chloride, 113 

Synthetic rubber, 86, 103 

Tapping, plantation methods, 76; 
wild rubber, 67 

Telephone, 218 

Tennis, history, 202 

Tennis balls, 202 



344 



INDEX 






Tennis shoes, 179 

Terpenea, 103 

Testing rubber, 49 

Thomson, Kobert W., 121 

Tiling, 250 

Tillinghast, P. W., 122 

Tires, bicycles, 120; history, 120 
manufacture, 125; cord, 138 
pneumatic automobile, 130 
pneumatic truck, 162; solid, 
152; future demand for, 332 

Torquemada, 64 

Transporitation, 149; future of, 
328 

Tread, tire, 60, 134 

Tube, inner, 134, 144; formula, 47 

Tubing, drainage, 260; Carrel- 
Dakin, 261 

Typewriter, 230; platens, 231 

Ultramarine blue, 62 

Van der Heide, John, 236 



Vermilion, 62 %■ , 

Viscosity, 107 

Vulcanization, cceflBcient of. 111 
cold, 113; discovery of, 9, 22 
organic compounds for, 114 
Peachey process, 114; time and 
temperature, 28, 110; theory of, 
108, 112; without sulphur, 114 

Washing rubber, 31; loss on, 70 

Water bottles, 296 

Water-proofing, 7, 182; See 
Spreading 

Weber, Carl O., 112 

Webster, Daniel, 26 

Westinghouse, George, 276 

Wliite lead, 9, 50 

Whiting, 46 

Wickham, Sir Henry A., 71 

Zinc oxide, 46, 60; particle size, 
117; for resistance to abrasion, 
55 



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